After a little web work it seems you are in charge of business development for Gaming Grids and also personally co founded Exertus Esports. You probably highly experienced at gaming community development and so thank you for thinking TF2 should be apart of your current venture with Razer Arena.
I wanted to highlight a couple issues which honestly transcend beyond the application of your tournament website.
The first of which is that the competitive TF2 community is a small tight knit community that really has never had vast numbers of players since it is hard for public play to translate into a competitive environment. The direction of the game as a whole went one direction and the competitive community went another. To the vast majority it is near impossible to find "fun" in comp tf2, let alone think about competing against people who play 40 hours a week.
The schedule of TF2 comp players is already highly saturated. For many seasons now comp players have had to deal with the fact that 6v6 and Highlander overlap and in some cases cause strain when it comes to having a team to compete in an "event." When you add in H1Z1, dota, and the other games people play, there is little to no room for more competition. At certain point people just want to enjoy their leisure time by moving a blob around a screen devouring other blobs.
ESEA has a monopoly on high-end comp TF2. The service is a joke in many regards but still serves as the staple of North American 6's TF2. Toss in ETF2L for Europe and you've got the two most popular leagues for TF2. ESEA usually provides little to no break between seasons. If I remember correctly during season13, it was a 4 day break for registration. I honestly cannot comment on ETF2L, but can only say that the league has done quite well for about 78 seasons now. Point being, if it comes down to playing in an event, people will always defer to ESEA, since it is considered the best, and people are paying for it. Value is implied.
The timing is also off. Right now is ESEA playoffs. People should be focusing on competing and trying to place as high as they can, take a break from high-end competition, and then come back refreshed to compete again. The last thing people are thinking of is to compete in an event that has no cash prize and no benefit (as far as I know). And even if there was a cash prize, all that would happen is that froyotech or ascent plays, wins the money, gets donations, and goes back to their routine.
What is the benefit of Razer Arena? From what I can see it is a partnership between Razer and Gaming Grids to try and compete with other web based tournament platforms in terms of amount of users and sponsors. If you provide no value, no one will play. Is there a 500 dollar startup tournament? Is there a community outreach podcast? Has Lord Enigma signed off on Razer Arena?
Organizations and sponsors have tried to help TF2 in the past, some have done more than others. But it is always the case that people are looking out for just themselves. If you are hoping for 40 teams to sign up, you need to get the "illuminated" members of the TF2 community on board. It goes much further than just posting on ETF2L or TFTV. Razer is a popular name worth over a BILLION dollars. So sorry if I come across as asking for a handout, but 95 percent of this community is likely satisfied with UGC and ESEA.
As a consumer, I am prepared to spend one more night a week playing TF2 on the Razer Arena, but I haven't been convinced, mostly because UGC satisfies that NEED.