Of course you're making a point -- the point that "sully could play better now that he's going to be next to Amir Johnson."
Or "Bass was often out of position or didn't rotate." That is also a point. A point you can't prove and a point that is almost certainly coloured by confirmation bias, but a point nonetheless.
I don't think Bass was a particularly good help defender, of course.
So wha'ts your point DOS.
The point is that Bass wasn't (and isn't) a bad defender, and saying that he was does not make it so. Qualified with the point that there is a difference between 'not particularly good' and 'bad.'
Why don't you go make a poll about it?
Brandon Bass is a mix bag defensively. I'd say more unreliable, than bad... particularly with complicated defensive schemes. I don't want to say unreliable either... inconsistent? At the same time he could be a plus defensively when really engaged. It's more "upstairs" than anything.
He makes up with some of his poor defensive awareness with quickness and ability to switch to multiple different positions.
His effort has been questionable also, but he's improved on that regard last couple of years quite a bit, and he usually shows up for the Playoffs (effort level wise).
But I also think he's a great option to have if you want him to shadow a player, though there's still the situation when gets lost (gets caught ball watching), when he's focused on that sole player he adds quite a bit of value. For example, when assigned to guard LeBron with mix results (mainly due to LeBron's talent level of course).
In all personally I've never liked what he brought defensively to the table. All anecdotal of course.