I totally see RTD's point re disabled villains (see also the way a god 50% of Bond villains--if not Moore-- are disfigured in some way) and making a decision going forward to no longer have villains in wheelchairs is absolutely ok with me, but Davros is an established character with a very established look, so either leave him as he is or just choose not to use him.
The Bond villain thing is always a weird one, because (a) Bond himself originally had a facial scar (b) because of its proximity to WW2, disability from injury was rarely seen as a hallmark of a baddy (except duelling scars, because that says ‘german officer’) and more about having gone through stuff. Time moves on from that, and the original more benign reasoning gets lost. By the same token, *most* Bond villains are not disabled, and even ‘disfigured’ are probably in the minority — but the ‘most famous’ one usually is, Blofeld. In fact… basically, outside of the Connery and Craig era, I find it hard to think of that many. Does Scaramangas third nipple count? Does Alec’s facial scarring count in Goldeneye, given we see what causes it? Electra had the eat thing I guess, and her boyfriend was also scarred up… none disabled though, and Craig Bond kept his scars all under his shirt.
RTD is just wrong on Davros though. I wonder what he would make of Sharaz Jek these days?
Not sure he’s even a villain.
In fact, I think RTD has written more overtly disabled villains than anyone else. He even made The Master have Mental Health issues as opposed to just being villainous. I spoke he gave the Doctor some PTSD too.