Can't the testnet be reset at any time by the devs?
Yes
No, it can't. Developers can reset TestNet only with new Bitcoin client released, by changing genesis block (won't happen since
they would lose
millions of coins they mined) or checkpoint(s). The fact
TestNet genesis block was never reseted speaks about what developers really are up to,
basically they don't want
late adopters to have more Testnet coins than they think late adopters should have.
That's not what he is asking. Yes the devs can reset Testnet. Period.
Except if for you changing the genesis block doesn't reset testnet because people can still use a modified client to access the old one. That's true but noone will ever give a fuck if the satoshi client doesn't include it