PSASBR is being compared to Brawl just because it is the most successful game in the genre. Yes both games are worlds apart to us but it sure doesn't hurt for a review to mention "just as fun as smash bros".
The real comparison will be in 12 months when Super smash bros 4 comes out. These two games will be the newest and best in the genre so of course they should be brutally compared. And of course they will be in direct competition.