Well it's the same as using BB spaces, or "disabled toilets" isn't it, some selfish fuckers still use these facilities even though they don't need to, they just want to. Despite justifying it with they were only a minute, or there was no one else there, or not wanting to disappoint their DC. If there is a facility for people with SN, and you don't have SN, don't use the facility - it's pretty simple really.
Some people are just selfish though and think only of themselves.