Let me put it this way, in 2006 terms:
You are the coach. All of your players are healthy. You only have room for 3 DEs and 2 NTs on the gameday roster. Here are the 7 you can choose your 5 from:
DEs:
Richard Seymour
Ty Warren
Jarvis Green
Marquise Hill
NTs:
Vince Wilfork
Mike Wright
Le Kevin Smith
...
The choices are obvious. Marquise Hill has been active for 13 games in his 3-year career, or just about 4 per year. He had 4 in 2006, 8 in 2005, and 1 in 2004. With NO starts, thanks to a certain Mr. Green. Keep in mind Wright had only started ONE game in his career before his stretch filling in for Wilfork, and that was as a DT when the Pats started in a 4-3 in Week 2 of 2006 against the Jets.
So really, the only times Wright has been active instead of Hill in Wright's 2-year career have come when he was the backup NT, not as a backup DE. He has just simply seen time at DE because he was active.
You can't fault Hill for not being active in this scenario. It's a helluva lot easier for Wright to beat out Le Kevin Smith to suit up than it is for Hill to beat out Green.
I wouldn't judge much of anything of this guy's play when the sample of him seeing the field when Seymour or Warren were injured was MICROSCOPIC.
Since Warren and Seymour are going nowhere, he'll (not) play out his contract with the Pats, and then probably seek a team in free agency where he can actually see the field, have a chance to start, and maybe live up to his 2nd round potential. But the Pats haven't, nor will cut him just for the sake of getting somebody "better" on the roster at the 4th DE position.