I don't think they look at it or get inspired because they actually belive they know what theyere doing but they also buff riven and eve again and give ahri another skin, her 12th skin.
OH BOY ARE THEY WRONG WHEN THEY BELIVE THAT WE HAVE BAD CONCEPTS AND THAT THEY DONT FIT IN THEIR PLANS THAT ARE GOING DOWN TO OBLIVION LOL*[sg-miss-fortune]*
Part of the hook is doing it for fun. Who doesn't like imagining their own characters or universes?
Riot almost never adds fan creations into the game unless they have overwhelming amounts of support and/or are high quality anyway, and even then they might not do it. Dragon Trainer Heim was one of the lucky, as was Pizza Delivery Sivir and Meowrick(formerly known as Crazy Cat Lady Yorick). And I believe champion concepts are entirely out of the question, due to the fact that they range from barely even a concept to insanely high quality and detailed.
No one here posts their fan concepts with the hopes of getting them into the game. They're for fun. If Riot wants to use an idea we post here, they can and will.
Sometimes ideas do get taken from the Community.
Braum and Kindred had parts which Riot admitted were taken from inspiration taken by posts made on this sub board. Some skin themes get through as well, as 4 step Cadence just mentioned.
So no it's not pointless, it's just a lottery draw, if we wanna stand to your singular point.
That said, nearly nobody makes the kits because they want Riot to see it. They do it because it's fun. You should try a little fun in your life, it would do you good.
