Partially Adapted Cabins

I have CP with a left side hemiplegia and I am a partial wheelchair user. When I have stayed in hotels or when I did a cruise on Independence of the Seas I have had a fully accessible

Wet room on cruise ship

accommodation because I require the use of a wet room.  Because of the nature of my disability I cannot use a bath.  
I have often wondered why I have rarely found accommodation that is partially adapted for people like myself who do not require the extra room needed to manouvre a wheelchair but need the facilities of a wet room.  
I believe that if cruise lines put a few of these cabins on each of their ships it would be a welcomed addition.  It was by pure chance that I have discovered that P&O's Arcadia has 12 partially adapted cabins and they are:  

C1, C2, C194, C203, E95, E96, G11, G12, G74, G81, G82 & G100.  

Again I have to wonder why someone like P&O did not consider putting a few partially adapted cabins on Britannia.  I have to ask the question again who do companies like P&O consult when it come to deciding what is required when it comes to adaptions for passengers with disabilities.  I assume that they may ask OT's (Occupational Therapists).  
I have had dealings with OT's over many years and have found some to be excellent while others are complete rubbish.  I believe the best people that they could consult would be disabled people because we can often find something that an able bodied person may miss.