Yeah, that's definitely the key here. Your mistakes are much less accessible to people who don't write or mix music (producing is both combined, btw), or even people who just began for a few weeks. Sure, you can put your music up on newgrounds and soundcloud and all that, but just remember that if the person who gave you feedback is someone you don't know, you really can't be sure how objective they actually are, so I wouldn't take feedback on either of those two websites too seriously unless you know the person well enough to have a rough idea of where they are in the music producing process (and even that's hard enough).
If someone says a vague comment, like "that sounds cool", "nice", "sounds neat", and so on, it's almost like cooking feedback that says such things as "this tastes delicious", "this has nice flavors", "I like it", and so on ("This is the best [meal name] I've ever had" is a bit of a step up IMO). Those kinds of comments are merely descriptors of how in awe they are. I found a cool definition of awe a few months back:
So when someone says something like that, even if it's not nice, then just thank 'em and move on. Not much depth to think too much about there.
Not to say that you shouldn't consider those people, though. If you satisfy them, then it tends to mean you have an arrangement that's easily likable or memorable.