I think what he's doing is trying to get people to focus on expectation management. Too much focus on the materialization of the spirits can make you lose your perspective and mistake a vision obtained for a successful rite, and overly focusing on the physical stuff you get as the outcome can blind you to the real benefits of magic and this hermetic stuff we do.
I think that's what Acher is focusing on in his advice, the outcome. And he values the internal outcome the most, the changes to the inner man within the magician, because that's what brings the peace, the stoic contentedness that he believes is an enlightened state. He is totally right, too, it is the internal changes to you that matter most. The person you become as you do magic, the harmonization of your spheres, the learning who and what you are that make you capable of doing whatever it is that you're here to do... That's the real reason we do the magic to manifest the world, because the process changes us into who we are, it teaches us the things we have forgotten while incarnated. It makes us fully human, i.e. divine and in the flesh at the same time, in harmony. That's beautiful. And that is more important than the flashy magics, in the long run.
But here's the thing... I also think people should be happy. I believe happiness is a spiritual tool, an indicator that points directly back to their True Will, their Providence, their Fate, their Destiny, their Raison d'être. I don't think there's a better or more pleasant way to discover and apply your Will than to go after the manifestation of what you want. Nothing will make you happier than achieving harmony between the things you do and the things you want to do. When your life manifests your desires, your Will becomes obvious. You learn Who you are, and Why you are as you pursue the things you want. You develop the ability to discern what you "really" want when you manifest things that you thought you wanted and they don't make you happy. You learn the spiritual lessons that reveal what it is that really makes you happy underneath the physical situations, relationships, or material things.
The material manifestations... those are just physical representations of Ideas to magicians like me, Hermeticists who are at home in the cosmology of neoplatonism. They are the clumsiest forms of the Idea, and are furthest from their core source.
But we are also in physical bodies, and the physical interaction of "us" with the physical manifestation of the desired thing reveals a physical harmonic that is a manifestation of the interaction between my eternal spirit sourced in the Primum Mobile that manifests as light in extension for the joy of existence and the Idea that is manifested in the desired thing. Manifesting what you want physically is awesome.
It's also a major part of why we're here, all of us. The creation and manifestation of our worlds. There's a reason it makes us really thrilled and gives us supernatural perspective, elevated understanding, a rush of endorphins, and the divine madness of being a god. It is beautiful, on purpose, as a signpost that you are doing it right.
So the problem a lot of people with spiritual inclinations have with this kind of ecstatic approach to finding spiritual attainment through the fulfillment of desires is that, quite simply, it is dangerous. I advocate focusing on pleasure because it can teach you about yourself. If you really apply your mind and your reason and your intellect and your constructive interest to the understanding of what makes you happy, if you go after your Genius and work with it to learn from your pleasures, you will succeed in awesome ways.
But if you let your desires master you, if you fall into the trap of just feeling the good feelings without applying yourself to understanding what the experience represents to you across the spectrum of the "worlds," physical, mental, spiritual, and how that impacts eternity, you're wasting your time. I tell people to go after what they want with the assumption firmly in place that you will do so under the umbrella, with the intent of "knowing thyself."
But I also have little doubt that you'll really be able to do any of the magic I recommend and end up on the wrong side of the left hand path. Yes, it's dangerous, but if you're regularly working with angels, spirits, and your HGA, you've got little to fear. They, and your own inner spirit that strives to be all that it intends to become, will ensure that even if you slip up a bit, you end up in the right place sooner or later.
So get started with the simple stuff. Conjure the spirits with the intent to get some money, or a new car, or a better relationship, or a career path. Look at your life, the things that you have, and the things that you do, and take a close look at how these things make you feel. Note the things about your life that bring you pleasure. Note the things that need to change in order to bring you pleasure.
Then determine the right spirits to conjure up who will bring you the desired results. Then conjure them. Then ask them to change your world. Then evaluate your results. Then determine if you're happy, and if so, why. If not, why not. Then decide what you want to do next, alter the existing outcome, or start something new. Then do more magic to get what you want, and see how you like it when you get it.
Repeat this, ad infinatum. Seek the Kingdom of God. Find it. Rule it. Let this process transform you from ignorance to understanding, from puny human to immortal god, from ignorance to transcendence (and back again). As you get the things you want, you'll be happy. As you see that you are powerful, you will become content. As you learn that the things aren't the fun, you will learn the mystery of why we're here, and the power of fun, and the experience of joy.
And you'll develop traction, spiritual muscles. You'll live a magical life that is filled with wonder, insight, and wisdom. You won't turn into an arrogant self-absorbed prick all the time, you'll know with each passed mile marker along the way that you are accomplishing your mission by keeping in motion, never stopping until you've been completely undone and put back together. You'll keep moving forward, onward and upward, you'll just keep swimming... I'm running out of trite cliches here, but give me a minute, they'll be back...
Traction. That's the key. You keep moving... like a shark.