I believe Meebo was purchased to become part of Google+ not to be an independently operated subsidiary of Google. This shutting down doesn't mean that Meebo will leave the internet space, it just means that the next time we'll see Meebo it'll be with a "Google+" logo on it.
Larry Page has been shutting down and consolidating divisions of Google for the last 18 months. This appears to fit his strategy at the moment. Why pay for two chat divisions?
They wanted the meebobar only, because it's cheaper than building their own, or it's too entrenched to compete against. Those are the only two plausible explanations that would make sense (to me, obviously) but neither actually make much sense when applied to Google.
Larry Page has been shutting down and consolidating divisions of Google for the last 18 months. This appears to fit his strategy at the moment. Why pay for two chat divisions?