If you think you can walk everywhere you need to go at USC you don't know much about its location.
We're talking about UW and the campus, stadium and area around it are awesome. UCLA campus and surrounding area is awesome too along with perfect climate since it came up (downside for football is the Rose Bowl isn't near campus, but that area is incredibly beautiful too). It's hilarious/sad people are so irrationally fearful of these places.
The on topic point is that Seattle itself isn't going to scare off any players or coaches, it's awesome. Maybe how geographically isolated it is for travel or recruiting, although they seem to get the players so I don't know why that would stop.