One- Chad Johnson (I refuse to call him by his ridiculous new name) missed the game because of a death in the family.
Two- I get that you hate him. I do to. Hell, I lived in Cincy when people were calling him the best receiver in the NFL. All of his antics were everywhere, and I hated the guy. But the guy does have some talent left.
This season, Johnson had 15 receptions for 276 yards and a TD. In contrast, Underwood had 3 receptions for 30 yards and no scores.
And while he has not been an all-star receiver the last couple years, his stats are decent- about 830 yards in 2010/2011, and over 1000 in 09/10. He is a solid 3rd option in any offense.
Now, as for your claim that it is a PR move- BS. When have the Patriots ever cared about PR? They play to win. And more often than not, they do.