Most people dislike the looks of a bare tank because it's "boring" and such, but I personally have nothing but bare tanks (gravel bottoms), and like it.
When I went from a planted and decorated tank to a bare tank, my fish
did begin to swim more (within 2-3 days), and of course had more room to swim. They also began to utilize the entire tank, compared to when it was decorated. My fish also became much less skittish, and became much more comfortable with me, after the removal of the decor.
Tank maitanance is
much easier, and much less time consuming.
The only thing I did when I removed the decor was to dim the lights in my tanks. I no longer had plants that needed the light, so there was no reason to leave the bulbs at full brightness.
Come to think of it, I can't think of one single reason (other than looks if that's your thing) that a bare tank would be considered a negative move for your tank and/or fish.