I actually don't mind this, but I imagine it'll set of a bit of a... lively discussion.
Also I'm really looking forward to seeing what all the people who complained about Chris Chibnall's era being "too woke" are going to make of RTD's second era. From what I've seen so far, he's really not fucking about this time lol.
Yeah I think a lot of Chibnals detractors are in for a rude awakening. Sure, you can say it wasn't woke for RTD1 but that's nostalgia considering he:
parodied Tony Blair with John Simms master
created an out and proud pansexual in Harkness
portrayed the Doctor as ambiguous sexually, accepting advances from Jack and Lynda (?) In parting of ways
the slitheen two-parter being commentary on the war on terror and false claims of WMDs
I think that in the time since 2010, RTDs writing experience and the general increase in right wing radicalisation since 2015 are combining to create these decisions like able bodied Davros or 14 regenerating clothes
I think RTD has cleverly side-stepped some of the fallout by setting this little story a little while before Genesis of the Daleks. It doesn't quite work with established lore, but near enough that casual viewers might say "oh so this is before Davros has his accident or whatever".
I don't mind the change, especially as the Davros story has been so told out now I doubt we'll see much on-screen for the foreseeable future. However, I would question if Davros would have seen himself as disabled. I'm not familiar enough with the canon to know if we ever learned why he was in the chair, but I always assumed that Davros had experimented on himself while working on the Daleks. Him being a transitory phase between the Khaled evolution and the future evolution that would become the Daleks. I saw his chair as a reflection of this mid-way Dalek.
As I said, I don't mind this change but I feel it is an ultimately empty thought if they don't have people with disabilities in the 'positive' roles too. It's all well and good saying he doesn't want to associate disability with evil, but that also has to be followed by normalizing folks with disabilities within other roles too.
The next episode has the wonderful ruth madeley, who is a wheelchair user helping the doctor. She also played a different character as a companion to the 6th in big finish.
I'm sure we'll see others too. Because of the number of evil wheelchair users in media over the years it's simply better to stay well away from this trope from now on.
It certainly invites unwanted conversations when a companion this season uses a wheelchair. If that wasn't the case, I would bet this would never have even occurred to anyone. It's probably a good thing to have the conversation.
As far as the in universe explanation, Davros is a mad scientist. He made new legs.