You've fallen victim to the classic trap of asking a different question in the first post than in the poll. Therefore, I can't vote.
To answer the poll question, "No" is my answer - going to a gym in itself can be worthwhile in terms of quality gained for amount of time spent. Although, by and large, "any exercise" fits in place of "going to the gym" for general health benefits. I say this as someone who doesn't go to a gym, because I want my exercise to be fun, and in my opinion, simply working out at a gym is not fun.
To answer the first post question, "yes", in my opinion, "fitness freaks" are not getting as much of a return as they put in, if their goal is to be healthy and enjoy the rest of life more. Like Leifmk said, if this is your thing, or if you want to be a stellar athlete, then by all means, a "fitness freak" lifestyle makes sense. But assuming you're only in it for the health benefits and don't enjoy it *that* much... being a "fitness freak" is more investment than it's really worth, versus a more moderate regimen.
But again, I've never really done that, so I'm not speaking from experience.