I like meat. Lots of it. After paying a visit to Mondscheinstüberl, I feel pitty for you vegans. Whilst the schnitzel I had was quite OK, the starter (some filled zucchini) was well advertised by the staff but tasted rather bland. The Bio-Beer tasted bland as well; however, it did a good job as I felt a bit woozy after two of them. All in all, it all tasted bland.
Don't get me wrong: The staff is _very_ friendly and _very fast_. The dishes ought to be great from an exclusive vegan point of view.
So all meat-lovers who just want to try out vegan stuff should probably search elsewhere (Vegetasia is great in this respect, however, it serves Asian cuisine and Monscheinstüberl offers vegan Vienna-style dishes, so they are not comparable).
Besides: the place is grossly overpriced in my view for what it offers. Sure, "Bio" - like "Wellness" - costs extra, that is a default rule. At these prices, however, you might want to try Wrenkh instead (which equally offers only bland dishes, but is more up-market in terms of "style").
As a result, one star is enough. Please note that this is my very subjective opinion. Vegans actually might like the place. And yes, you are right. Dissing a great place like Monscheinstüberl as confessing meat-freak is like a heterosexual going to a gay party and dissing the crowd for being gay.