Hold up there sparky. The axetinguisher is not supposed to crit if the enemy isn't on fire. The descriptions says that it has 100% crit on burning enemies, 50% damage to non-burning enemies, and doesn't crit on non-burning enemies. It sounds like you've actually found a bug, not something meant to be in there.
Also, yeah, pyros have always been able to torch people if they bounce along the surface. However, they still don't catch on fire. Also, the backburner does not say that it won't crit unless it hits the back. Sounds like there are problems of you just getting burned by random crits. Besides, the pyro is now actually what it's supposed to have been originally. Pyro was meant to be the king of close-range combat. Previously a pyro and a soldier/demoman/heavy at point blank or otherwise close range with both players at equal skill level would ALWAYS result in the pyro's death. They just had higher damage output at that range. Besides, I don't really think it's fair to be calling cheap just yet. Remember, pyro is the only class meant to fight people that's actually gotten weapon upgrades. You may be crying broken now, then call it underpowered when the soldier, demo, and heavy get their turn. I will admit though that I hate the number of pyros on every server out there. I try to pick pyro on my team if there's 1 or 2 because it's been my primary class for quite a while now, but that's soon down the drain when another 10 people decide to class switch to pyro also.