The difference is though Batman Arkham Knight has a decent-great game buried underneath depending on how you feel. Tony Hawk could fix everything and it would still be an unfun, poorly thought up, rushed rip-off of a game.
It is a mess on the molecular level. It is conceptually and literally a mess.
You stated exactly why Tony Hawk should be most disappointing, the return of Tony Hawk Pro Skater was an unfun, poorly thought up, rushed rip-off of a game, how is that even possible? They took a series like Tony Hawk and drove it into the ground, which I think is more disappointing than a hot mess.
Batman on the other hand was an absolute mess in every way on PC, the way WB and Rocksteady handled the whole situation, having Iron Galaxy come in 3 months before release and try and push out a PC version, the Nvidia videos that were full on lies with sped up gameplay to make it look like it ran at 60fps, but the game had a 30fps lock. The fact that it was removed from Steam for months and just now re-releasing with a $10 price drop and still a $40 season pass. The game is still fucked, they just said W10 users should have at least 12GB or RAM if they want to avoid stuttering. I could go on, but I just don't see how anything could possibly be a hotter mess than this.
But everyones definition of what a hot mess is different, as it's an entirely subjective term.