Not specifically addressed to this post, but you get the feeling generally that some fans are so tied to their prediction of his impending failure that they are missing the pleasure of the great performance Hairston has given the Reds. Freel is also not given his due as a player.
In terms of their ability, guys like Hairston, Keppinger, and Freel add a great deal to a team. They don't cost a fortune. They have the basic talent to provide a good performance. They hustle. They're versatile. And they are necessary because everybody can't be a $10 plus million superstar.
I have no doubt that Hairston will continue to perform well, he does not look like a flash in the pan to me. Similarly, I always thought that Freel added a lot (despite some errors of aggression). Freel plays hard and, in streaks, can hit. He plays multiple positions including a reasonable centerfield.
The Reds' failure with Freel was not overestimating his talents, but being too optimistic about his ability to stay healthy. He was a major injury risk and that was the flaw with his deal. Hairston seems to be a similar injury risk. He's been hurt much in recent years and probably can't be counted on for a lot of games.
The big issue with these guys is the injury risk, not performance, IMO.