While Curry, Dantley, Barkley and Harden were "defensive liabilities", they weren't the to the degree that Roberson is an "offensive liability". The only example that I can think of is Isaiah Thomas and I'm not even sure he is a defensive liability to the extent that Roberson is an offensive liability. The people you are talking about aren't great defenders. But they aren't non-factors on defense like Roberson is on offense.
Thats why I mentioned Ben Wallace, career TS% of 47.4%, compared to Roberson's 52.9%. Most great offensive players aren't horrifically bad on defense, simply because athleticism tends to translate to both sides of the court. Isaiah Thomas is the only player I think matches your description, and his best season still outclasses Wallace's best season in WS/48 but not BPM, with Wallace's best season being .190 WS/48 and +5.9 BPM, compared to Thomas' season of .234 WS/48, but only a BPM of +5.4.
It's dumb how Skip Bayless the LeBron hater/Westbrook lover changes his argument. Ever since Bron started getting triple doubles he has been whining about how they don't matter and how he's just statpadding while playing no defense. Yet when Westbrook gets triple doubles Skip Bayless is his biggest hypeman.
