I can understand the possible problem with some "so called" celebrities not wanting it to be revealed how unpopular they are with the public, but I'm sure the BBC would like to hide how comparatively few people bother to vote, compared to the viewing figures.
I'd hazard a guess too, that since the programme now attracts people who aren't as interested in the quality of the dances, as many of those who've always appreciated a good standard, the percentage of votes of the total viewing numbers, has dropped even further.