Yes, shit tobacco is shit tobacco.If you mix 5 different kinds of shit together, you still get shit. No harm in experimenting but it seems like it would be a miracle if some fantastic tasting blend arose from those ashes.
The thing is though, that most reject whatever blend because of taste, not because it's shit.
Most of the blends I didn't like I've been able to alter to suit my tastes.
By mixing different blends, one often balances out the other.
Also, time can do wonders for some blends [AJ's Vaper for example], so I suspect that many bitza blends benefit from a bit of ageing.