Well dreaming is just your imagination going a million miles an hour...

During the day... that part of the brain tends to relax.

During the night, the Day parts of the brain turn off and the imagination center turns on.

So i see no harm in being 100% lucid all the time.

It's just swapping around the brain areas for different usages.

The part of the brain that is active during LD, my beleif is, is NOT used in day to day activity.

Rather, it get's an ECHO of your day to day activity. (memory is stored all throughout the brain in random locations.)

I'm kinda hard to read here so I hope this makes a bit of sense.