You can call it laziness, sure. It's all about convenience really. There's no reason to put it in the tournament forum. The only possible reason is to cut down on traffic. GM is basically the centre point. That is where the vast, vast majority of tennis discussion goes on and that is where most people head to when they come on MTF. Why on earth would you tuck live discussion away in the tournament forum, then? The only reason I can think of is because you think GM will get too busy.
It is pure laziness, but that is just semantics. The simple reason is they should go there, is because that is what the tournament forums were set up for, not just for Entry Lists, to discuss the individual matches in that respective tournament in the Order of Play threads.
These matches involving the big stars doesn't deserve any special treatment in having a thread just for them, and neither does Oscar Hernandez, but we can keep doing the circle thing.
The reason I know that is because even if you put live discussion in the tournament forum, you still leave open the possibility of encountering every single problem you anticipated would occur on GM. If by magic everyone could be bothered to go to the tournament forum and use the live match thread, every single objection you raised is still something you would potentially have to deal with. Like I said, the only explanation is that you are trying to cut down on the traffic.
You'd get that anywhere. There are mods that look after the tournament sections. Jinnxing, the fake scores and the other shit would get warnings and told to move to gamblers lounge.
In other words you are saying posters are too thick or too lazy to click on the upcoming tournament Wimbledon for example and talk about the live matches in there.