Boothe has one year left on his deal, and will turn 30 next year. If we drafted an OL, they'd have plenty of opportunities to play immediately given the frequent injuries, and significant drop off largely due to age (Snee, Baas) etc.
You have to think long term with the draft as well. How many of these guys are going to be on the team in 2013? Beatty, Boothe, Lockear all have expiring contracts.