It's bad because it can pollinate your females! You don't want your female plants pollinated, because depending on the degree of pollination it can seriously reduce down your yield as the females put all their energy into producing seeds rather than unfertilised calyxs.

Yes it can get you high, other than the odd male flower it behaves in exactly the same way as a female plant. And yes it does flower - it behaves in exactly the same way as a female plant.

Because hermaphrodites look to all intents and purposes as regular females, it's very easy to miss the odd male flower lurking under the foliage - the next thing you know all your females are pollinated - that's why people don't like them!