Why is it?

Most of the people saying this are doing one of two things, IMHO, they are either watching the ball only, or they are watching Bush only. They are not watching the other players on the entire field and how each play is developing.

Notice that Defenses that do the latter are getting torched.
Shadowing a good player is common in the league, and defenses will usually try to roll coverage to the hot player, Tampa especially because of the 2 deep zone coverage from their safeties.
See the first TD pass to Devery, Colston got the safety to bite on the out route while the other safety was rolling towards Reggie's side and Devery got in between them for a 50+ yard catch and run for a score.

Reggie does need to work on his field vision, which will come with more carries and some experience. Let the haters hate and leave 'em to their misery.
I'm quick to flip that 'Same ole Saints' switch, but that may just be a conditioned response from years of abuse. So I can sort of understand where they're coming from, but it won't bother me as long as this team keeps giving it 100% every game.
That's all I wanted out of them this year, was to not quit or give up and play good, smart football. They have exceeded all of my expectations.