Originally Posted by LarryJ

I don't think that would work well.

That would require an earlier cutoff for boarding passengers so that the wheelchair passengers, whose boarding is often time consuming, can be accomplished without other passengers being in the way. It creates a problem with the ramp personnel having to process and stow passenger mobility devices at the last minute including the proper processing and paperwork associated with wheelchair batteries. Lastly, passengers with disabilities are more likely to be traveling with other medical assistance devices which must be allowed in the cabin. Room would have to be made for those devices, even after all in-cabin storage locations were filled.

All together, these issues would lead to more delayed flights. It would also be problematic if mobility-impaired passengers were given the added burden of having to reclaim checked carry-ons further delaying the wheelchair personnel who are needed to assist other passengers. All of this is mitigated by boarding (almost) all of the wheelchair passengers early in the boarding process.