Most things aren't. Euros aren't legal tender in the U.S., for example, and vice-versa. If Bitcoin were legal tender it would only mean that if someone owed you $50 they could offer you $50 worth of Bitcoin and you would be compelled to either accept the Bitcoin to pay off the debt or give up on collecting at all. No one is seriously suggesting that Bitcoin should be made legal tender. A number of Bitcoin supporters would probably rather do away with the idea altogether. I can see a use for it, though; an arbiter (public or private) may well decide not to hear your case unless you agree to accept a standard form of reparations, as other party may not have access to the specific goods owed. That would be well within the arbiter's rights—as long as they aren't preventing you from seeing justice elsewhere.
Yes, precedent was surely set when EVE Bank failed. Oh, wait.
EVE is a game. The players are aware of that. There is no expectation that anyone will step in and enforce real-world rules inside the game; that would ruin the game. Bitcoin is different. The protocol is just as virtual, but the contracts relating to it are entirely real, and ought to be just as enforceable as any other contract.
That doesn't mean any particular government is obligated to do the enforcing, of course, but they claim a monopoly in that field; if they're not going to uphold perfectly legitimate contracts themselves they at least ought to step aside and let someone else do it.