I think people don't realise the novelty of having your team on a t-shirt. Sure, I mean if I were to win one, I'd never be wearing it but that's besides the point, there's been numerous tournaments with prize pools with some reaching into the thousands, and I STILL get more hyped for a WNL phreaky t-shirt because it represents an achievement with your team.
I'd much rather have a cringe t-shirt that I'd never wear with your team's achievement rather than 30 euros which would buy me a takeaway or a tragic game to add to my steam library which I'll never play. I'm sure people would use the money maybe for bills (especially in poorer countries), but Warband isn't a job and shouldn't be treated as such, in a lot of hobbies you usually end up winning a trophy with a t-shirt and only start earning money when it's a job.
It's just cringe that people would rather take money, like bro, just enjoy what you get.