Arguments Against Treasuries

Keynes had mentioned his position in TLT.  I think his logic has merit and particularly as a tool for selling covered calls.  However there are some aspects of treasuries that seem troubling:
1.) They've already had a big run up.  When you have a good amount of demand in that particular area it gives it a lot of room to fall.
2.) Supply is massive.  The government will be issuing tons of these.  So much so that the Fed will likely be a buyer to keep demand up.
3.) The case for diversification in central banks.  While all the noise about changing reserve currencies is more smoke than fire, the idea is still out there and will likely have more than 0 effect on the holdings of central banks.  Once again you've got a huge amount of demand there with the potential to dry up.
4.) Inflation.  Inflation.  Inflation.

Color me a bit skeptical.