Personally I'd prefer to keep Barry and let Garcia go, but I suspect it's ultimately a financial decision. Barry is reported to be on £120k a week, far more than Garcia, and in the last year of his contract.
It looks like a new deal won't be offered so the club are keen to get whatever transfer fee they can, and get another high earner off the books. Soriano and Begiristain have said they're unhappy with the wages being paid to backup players, and we're overloaded with midfielders at present. It looks like they want to free up space in the squad (and on the wage bill) for a new centre half.
It's harsh, because Barry has been an excellent servant to the club, but football is a harsh industry. Barry is well recompensed, and is too good to spend a season on the bench at this stage of his career.