Just a theory...

I was thinking, that it’s probably likely that your subconscious doesn’t want you to have LDs. I mean, it tries to stop them occasionally (via false awakenings). It might be because LDing interferes with your dreams, which are an important form of outlet for your subconscious (or so I like to think), and LDing just doesn’t let this happen, because your conscious takes over. Anyone agree with me on this one?

Hmmm,im not sure.
As far as we know REM period is important for nature and our survival,there are theories that it is evolutionary thing.Taking it as a basis it leads you to thought that its just not really necessary to be councious in rem therefore we just dont use it.Its similar with to i.e math or memory skills…once we stop training it,our brain take it as we dont need it anymore and said skill slowly decreases.
I think this guess is closer,but as allways its just an opinion
take care