Yeah I've experienced that issue with people down voting and that is something I really like about Tapastic. Since we're not competing anything we tend to be a lot kinder to other artists because we aren't getting petty and competitive. However I've also noticed that series that I really could have worked harder on getting 6 ratings while series that I poured my heart and soul into tend to stay a steady 8.
I personally think that the tweeny atmosphere is because Deviant Art advertises the stuffing out of Webtoon. Like they post about the contests and stuff pretty regularly there and so then all of the young future artists flood into that site and kindof nest there. I think thats a good thing though, I started out on LINE, got a feel for the online comics community and fell in love with it. I wouldn't have found the loving Tapastic community I'm currently in without it and I still get really excited when I read the comments and suggestions on LINE (Because all my series are uploaded to both platforms)
I actually came back here to Update though, Webtoons has a secondary way to pay artists who get popular in the discover category! (while maintaining the ability to upload anywhere). LINE added a button to artist pages that directs to artists patreon accounts and if you gain 3k followers and upload regularly LINE will donate a certain amount to your account! I thought that was pretty neat.