There is nothing wrong in being a Drag Queen, nor of them reading to children, though I am not sure what the children would make of them - possibly think the drag queen is a pantomime dame.
Nor, in principle, can there be any objection if children dressing as drag queens. The danger is where they are performing and how the audience is responding. When, as in the original article, these children are being turned into objects of sexual exploitation then it is going very wrong indeed.
The same problems arise with child beauty contests. In principle there is nothing wrong with them - until the children start to be encouraged to cavort and pose in a sexual way and the inevitable perverts start getting involved.
However, this isn't something that is happening widely, with every other child involved. As with beauty pageants, far more is written about them than, the number of children involved justifies.
It is a matter of concern and one would hope that both the police and the NSPCC were keeping a close eye on both children performing in drag and beauty pageants, but the numbers involved are unlikely to be very large and I think the vast majority of parents would not let their children get involved in anything like this.
There will always be people prepared to exploit their children for gain or self gratification and not mind how they do it. There will always be those in the media and arts world who like to flirt with anything that seems dangerous, or edgy and beyond what the majority of people consider acceptable behaviour. But the fact that all these things are being performed in public where others can see and the relevant authorities can monitor it, makes it a lot safer than what occurs in secret and in silence.