Need help! what to do? Seems like they don't like my idea.

I know the feeling. Trust me.

It's always important to work on something you enjoy and something you believe in. Once I learnt how to deal with what I call "like" syndrome I got over the hunger for immediate [positive] reaction.
Recently I started creating ionic templates. No buzz for a good 2 months and then out of the blue Masahiko Sakakibara (well known in Japan ionic community) tweets about them it started picking up traction and then week after Sarah Drasner from Netlify tweeted about the templates and then things really started to pickup.

Keep working on it, but be realistic if it doesn't workout then its okay to put a pause on it. There are so many projects put on hold out there but you won't hear about them.

I can recommend reading "The Mom Test", I'm sure this book has been recommended a million times here but it's worth a read in regards to this issue.

I think the reason why you got such a negative response is that you are entering an already saturated market, here. With both Unreal Engine Marketplace, Unity Asset Store and especially with Epic gobbling up Quixel and bringing many of their assets free to the Unreal marketplace, I am not sure if there is really that much demand unless you have something unique or specialized that is not covered already.

Not sure a poll is necessarily the best gauge of how good of an idea this is. There are plenty of game developers who know artists to work with. The denominator seems irrelevant because the important number is how many people are interested.

It looks like you're trying to created a two sided marketplace right off the bat? That tends to be pretty difficult unless you are capable of generating a large number of assets on your own.

People hate facebook, just fyi :)

If it solves a problem/hits the brain the right way - it will work.