The issue isn't just the 172 pre-reg, or the fact that MKX is a consistent Top2/Top3 game in the FGC now. It's also that this is the first major for Mortal Kombat XL, a game which is not only adding 4 brand new characters, but also a rebalance to the entire cast that everyone is waiting to see.
This is our equivalent of AE or Ultra -- it's a big deal, and this is the first stage for it. A lot of people made their way out to be there.
Tekken's a given in ATL, but Xrd, DOA and Marvel are also logging a lot more stream time in pools. So it's not a Tekken-related issue.
I'm not one for wanting a community to sound 'entitled'; but at the same time, this isn't a situation like lake in MK9's life with 56 entrants begging for stream time. This is a tournament with what will likely be close to 200 entrants day of, with a major new patch, an entirely new version of the game.
If you complain about it, it becomes "oh those crazy MK guys, they're always complaining", but the obvious slight is obvious. And any game community pulling the same number of entrants would raise similar issues.