What do you mean paying for a service they may not be getting?
If you're booking last minute (less than 4 days when most of the 'free' seats have been given away) then it is common sense that you are likely to be split up.
Rows 31 and 32 are often blocked off especially at the window seats, these are for PRM users. However I have seen at check-in that PRM users are sometimes allocated a total random seat.
FR have definitely changed the seating algorithm, however it doesn't always work favourably for PRM passengers. I refuse to show sympathy to those who complain about not being seated with their travelling companions (adults) because they did not purchase a reserved seat.
NE