I haven't been watching Spike's 4th and Long despite former Tar Heel Jesse Holley's appearance as a contestant, but Blogging the Boys has, and succinctly explains why it's a waste of time:

So far, there hasn't been a defensive back on the field that looks ready to compete in San Antonio. On offense, Andrew Hawkins has some quicks and has shown he can run with the ball some after fielding a punt. Truly, that's the only way I can see a WR competing in San Antonio. Jesse Holley has also looked pretty good. But the top four receivers on the Cowboys are set. Roy Williams, Miles Austin, Patrick Crayton and Sam Hurd are not going to get beat out by anybody on the show. Isaiah Stanback's position is still a little shaky on this roster and his recent injury isn't helping his cause, but he's still more likely than not to make the roster. After that, draft pick Manuel Johnson is waiting to prove what he can do. Even further down, you got Mike Jefferson who was recently re-signed and UDFA's like Kevin Ogletree and Julian Hawkins. You better be something special returning kicks to beat out all those other guys as a receiver.

Too bad. Hopefully Holley gets a better shot with another team.