What country are you from in the first place? Where my home is its a profession legally just like any other, along with prostitution as well. It's quite strictly regulated and governed in its way. Not everyone does it, not every one approves of it either, but its the person's choice so why get upset about it. So why not pose with them?
Just personally I think the attitude by many North Americans have that because they view things a certain way, no one else should do it, or there should be laws made against it, or its negatively influencing children. I think encouraging children to avoid certain people because of their personal beliefs or choices is incorrect. Edcuating them about a range of possibilities IMO is better.
North American media on all boards show more violence, killings, psychologically disturbing images on day time TV that can severely adversely affect children than equating those who make a living by 'removing their clothes' as ones who should be avoid. They allow video games showing graphic violence, blood, etc. which though it has a rating on it, often the parents buy for their children anyway or they get a hold of it.
Since ATP is an international association of men's tennis I don't see why they should have to conform to one country's conservative view of things. However, they might have started and be based in North America, I don't know but I see no reason why it should be considered pathetic or incorrect.
Imposing one's own religious and conservative views on certain topics is intolerant I believe, and one of the main reasons why there is so much strife in the world, so much discrimination. Exaggeration over certain topics is another other.