Unova Defense Force, to the rescue once again ._.
I imagine for a lot of people, Gen V is still the worst generation - although how anyone could think that after playing Gen VII is beyond my comprehension - but it all comes down to personal perspective, really. There is no objective way of measuring what is the "best" or "worst" instalments in Pokemon (or any franchise, really) unless you want to take unrelated factors like sales figures, review scores, and majority opinion into account...and none of those things really impact on your enjoyment of it anyway, do they?
If you think it's the worst...well, good for you, I guess. If you think it's not...yeah, good for you, too. Personally...well, before I played Sun/Moon, I would have agreed with you about Black/White at the very least, although I would have held B2W2 as better than Gen VI. Now...part of me wants to go back to Gen V, because in the wake of Gen VII I will probably be a lot more forgiving of what nearly put me off the franchise when I first played them.