All I will say is go to Crewe and compare it to Newcastle Under Lyme. Crewe is owned and ran by Arriva. Newcastle Under Lyme ran by LAs. Newcastle-U-L is by no means fantastic but it's functional and it's tidy. Crewe is rarely (if ever) cleaned with the rubbish just flying about.
There are good and bad on both sides but I would say overall, bus operator owned bus stations are in poor state of repair and not very passenger friendly
Crewe hasn't been operator owned since Crosville was privatised, it was sold off, along with most of Crosville's other property, by their new owners ATL.
Since that time it has been owned by several development companies, all of whom failed to deliver grandiose plans for a new shopping centre & bus station. Following the failure of the last scheme several years ago, it was apparently purchased by the local council, who also keep promising imminent redevelopment !
If I remember correctly, Crosville actually closed their garage, which is on the same site, in 1988 & relocated to a new site within the town as closure and demolition was expected within weeks, only to move back in the following year when the redevelopment plan failed.
I wouldn't have thought that any operator would want to invest capital in a facility they don't own & know may be subject to sudden closure so I think they can't be criticised for that.