I wouldn't say making games is futile. The amount of 'luck needed' decreases significantly with experience. Sometimes it's because of the experience itself (making fewer rookie mistakes, resulting in a genuinely better game) and sometimes it is based on a bias (AAA veteran dropoff studios get more press than a 18 years old basement indie on average, but not always).
What's more, there are 'yes-men' everywhere, they will tell someone else their idea has value, even if it doesn't. I've put myself in a position where I can afford to say no, I pick my projects, and I never have to take on projects I don't think genuinely stand a chance. Of course, some projects are more risky, but the work being done isn't any less valuable there.
I've always been very self-conscious about my value in the industry, and for the past 6-7 years, I've kept a close watch on whether I was 'profitable' (even before, when I was still an employee). It matters to me. I also engaged in gamejams (notably the Week of Awesome II, III, IV) just to make sure I'm still relevant, that I can still do the work, etc. I'd hate to be a fraud, so I keep on testing myself to measure the extent of my abilities.
So, it is entirely possible to be inspired, but getting paid is also the means through which you secure serious developers: people that aren't just there because they need to (if you want some of THOSE, there's thousands on freelancer.com, and my experience working with them is consistently bad at best!)
My line of reasoning is, if the work I did so far has proven time and time again that my work is worth (more than) the $ I'm asking for, this is fair, and nothing like 'dreaming'. Now, how to assemble that work in such a way that it has value, that's actually the other person's role (it's their game after all) but even there I try to help because I do care about what I work on. I'm past the point of needing to work on projects for the sake of money, I'm at a point where I want these projects to have a legacy of their own. But luck still plays a huge part, and though I take serious risks on my own games, I shouldn't take the bulk of the risk when working on someone else's idea, that's where I draw the line. It is a professional service exchanges, in a market that's governed by capitalism. There's nothing wrong with it, and even if there were, these are the rules we've all agreed to operate with (although I'll admit I've done more than my share of barter to lessen costs).
It would be different if we were talking about 50 50 partnerships, which we're not: my contracts clearly state that the ownership of the work is my clients, not me. They get to reap the massive upside, so it makes sense to also face the appropriate level of risk. If one of these projects skyrocket, they make tons, whereas I won't, so why should I take that kind of risk?
Also, the simpler, shorter answer is: I can afford to say no to every rev-share because I've got more than enough paid projects, so why should I take any risk if there's simply no upside to it? (whatever will be said of rev-share based projects, they're still generally less promising because the reasons that led someone to rev-share in the first place is a good indicator of how shaky the foundation is).