That's because all the critics analyzed it before learning about the money involved.The Reds' acquisition of Scott Rolen is "without question the most widely panned pre-deadline trade within the industry."
No one said that the Reds got hosed on the talent level, just that Rolen makes too much money and this trade makes it harder for the Reds to do something else since it limits the teams payroll flex. That is what BP, Fangraphs, everyone at ESPN, everyone at MLBTV, and everyone else I read said.
Now if you add in the fact that the Reds will receive around $7M in the deal, it makes much more sense. The Reds add no payroll this year, and only add around $2M next year. Throw in the money saved by trading Hairston, and it's only around $1M.
So the Reds still have basically the same payroll flex they had before the trade, but have upgraded from a guy everyone knows is not a starting 3B, to one of the best in the majors, both defensively and offensively. Rolen is easily the best defensive 3B in the NL, and would be the 6th best offensive 3B in the NL (top ten in the majors).
For that the Reds gave up that previously mentioned utility player who will make close to $5M next year, a 27 year old rookie relief pitcher, and solid B+ prospect.
And they kept their payroll about the same. Had they increased their payroll by around $7M the trade makes no sense, so the money is very important, and something that every commentator on the trade missed.