The way i see it. it is like the cards are stacked and the odds against a free choice in things. That is detirminism. Free will is the magical x-factor. The thing that upsets a perectly well constructed culture, society, universe. It is the unplannable, the abstract, the adaptable. I think therefore i am .
The way I see it, your brain tells you what to think, what to do, what to look at, what to consider, what to perceive, and so on. What your brain tells you is based on the information your brain has acquired for you (whether genetically through evolution and heredity and/or via your personal environment and situations). Just because we're unaware of every single detail involved in our personal lives that affects the personal decisions we make doesn't mean we should acknowledge free will.
I would say adapting to any new environment is not a result of free will but, rather, an effect of a process involving a set of related/unrelated factors that led to this adaptation. It was inevitable that you would adapt eventually. Nothing would've stopped you from adapting. The same could be said in the case you never adapted.
Also, what necessity is there in having an entity that has yet to be clearly defined and that has no real purpose if things can be explained without such an entity? Occam's razor suggests not to involve unnecessary and unneeded entities if things can be explained without them.
Then there is the matter of psychopaths/sociopaths (and clinical narcissists and histrionics and such). These people can't really change the kind of destructive people that they can be. Unless they undergo some extreme psychiatric treatment (which has yet to be discovered), they'll never ever change for the better and become genuinely loving people who actually care for people other than themselves due to their personality disorders. What free will do such people have?
Other than that, I do not see the concept of free will as destructive. Rather, I see it as a harmless illusion that's just not necessary for our existence and the existence of this planet and this universe.