Why Do FPS typically have the best graphics?

[Doobie_wop]

everdom said:
Because games are becoming more and more reliant on pretty graphics to put themselves above the competition.

This is most evident with FPS's because the core mechanics across the genre are almost identical, really it is the only way to tell them apart. Because of this, selling as an FPS depends on graphics for moreso than any other genre, hence the pretty graphics war we have going on at the moment.

The Call of Duty and Halo franchise are the two best selling of the genre by a large margin and they also look very unimpressive compared to Killzone 2, Bioshock, Battlefield: Bad Company 2, Metro 2033 and Crysis, all these game's have only sold under 3 million copies each (except Crysis, can't find any data). I'd take a guess that FPS fan's want decent graphics's and just different styles of gameplay, anyone that tell's you that any of the FPS's that I mentioned play the same then they are wrong. 

I'd argue that TPS's have best graphic's.