Really, an MBA is only "necessary" for a middle-management position at a large corporation, where it's the standard entrance ticket. Everywhere else, you can get by without it. Clearly in technical circles, people see little value in the degree.
That's not quite the same thing as saying the the degree has no value though. I think the jury is still out on that one. I think it can be easily argued that "stupid business tricks" are an important area of specialty, with lots of subtlety. Not knowing those tricks is going to put your startup at a disadvantage in some situations (as other point out though, that probably doesn't include early stage development). And there's probably a lot you can learn in a classroom about that stuff. So I'm not going to condemn the MBA without evidence.
That's not quite the same thing as saying the the degree has no value though. I think the jury is still out on that one. I think it can be easily argued that "stupid business tricks" are an important area of specialty, with lots of subtlety. Not knowing those tricks is going to put your startup at a disadvantage in some situations (as other point out though, that probably doesn't include early stage development). And there's probably a lot you can learn in a classroom about that stuff. So I'm not going to condemn the MBA without evidence.