Are you saying you have big hands or something? Because clearly you can assemble them again.
I should be in jail by now, with a death sentence. Anyway, how badly the parts are damaged all depends on how careful you are to take the minifigs apart. Plus, half of the time, it's practically microscopic damage that not only is it not noticable, but it usually doesn't affect the MOC at all.I clearly am not a purist. I love Brickforge and Brickarms, but that is because they are very high quality parts.
However, I am the one to wag (or wave ) a finger at people who use clone brands in their MOCs, like Best-Lock or MegaBlocks for example. Mostly because they are mimicking Lego products, as to where Brickarms for example makes Lego Compatible parts. There is a giant difference here.
EDIT: Wow, I got an 8.95/10. And here I was saying I wasn't a purist.