Tbh I'm not surprised it was raised so quickly. For one, this is the only community fundraiser (that I know of) for Insomnia. Usually, there are like 2-3. 1-3 for various teams, and one for production sometimes. With there only being one, there's less of a chance of a split pot or the community's money being fractured across various fundraisers.
Two, they're only asking for 2 grand. I feel like the last time two teams were sent it was more like roughly 4-6k was the goal per team. They also have very good experience oriented goals. Most of the perks for other teams held no group encouragement for reaching a certain goal (other than a team attending LAN), only a certain amount of perks for the individual donation amount.
Three and probably most importantly the team, Froyotech (or b4nny depending on how you look at it), has the biggest consistent/dedicated fanbase, purely because of the fact that b4nny is the most consistent/dedicated/popular streamer for competitive tf2. It would make sense that the fans that already support him through twitch subs would pay to see him compete globally.
TLDR: not surprised cause 1. No team has a fundraiser right now 2. There only asking 2 grand w/ good community experience oriented fundraiser goals 3. b4nny has a consistent fan base.