Yes, it is perfectly normal for them to sleep on the floor of their viv. My beardie has done this her whole life.
Not all beardies take to the hides..... which can be a good thing. Your beardie obviously feels safe enough to sleep out in the open instead of hiding!
I wouldn't worry about it. They all have little minds of their own.
My beardie used to sleep where ever she happened to be when lights went out. Now I generally have her on me and place her on her fancy pillows - and she doesn't move til lights on. I'm thinking of building her a little hide but I have to find the time for it....
Beardies seem to have very strange sleeping habits. Mine, for example, loves to sleep standing on his hind legs against the glass. At first it seemed odd and uncomfortable but after some research I learned this was a normal behavior. Whatever works for them I guess
Mine sleeps in a different place every night. Sometime up against the glass off the climbing log, other times curled around herself in the hide. Seems normal to me.