I've always thought the people standing there were just doing it to distract the server.
There are probably a lot who think that way. I doubt many who have been told to stand there really know why they should be there. But the spot has many advantages - you can easily call the center and service line for your partner (they only need to worry about the sideline), it already has you ready to shade to the side to help your partner if the server hits a good wide serve (your partner probably won't recover in time so you'll be playing 1v2 for at least 1 shot), it puts you in the middle of the net man's possible angles if he poaches (aside from if they chase a very wide crosscourt return and get to it, which is when you need to follow them a bit to the side and cover more down the line), and it covers as much of the empty space between you and your partner as possible if your partner hits it to the net man - you just need to try and get a racket on it and put it back in play and force them to hit another winner.
You could say that I guess it depends on the relative strength and weakness of the player in questions two wings. But I think you have more viable options if you take the T serve on your bh, unless you've mastered the Bernard Tomic fade fh.
In singles, sure. In doubles, no. In singles, you get to start with your better shot and can hit heavy topspin to their backhand or hit a heavier and deeper shot to the middle of the court that they can't attack. In doubles, a good net man will be crowding the net and able to reach basically EVERY shot you can hit unless you hit it short into the alley, which is incredibly tough. Not only that, half of the DOUBLES court is exposed so they can just bunt it to that side and win since your weight is moving the other way. Inside out or inside in forehand from a righty on the ad side or lefty from the deuce side is better. Your partner can shade over to cover the middle while you go for your weapon and you guys can still cover most of the court. Also, the net player will have a harder time since the range of angles you have is much better. Run around forehands in the center is basically giving up the point against decent players though. I basically told a guy I was kicking the ball up the T to his backhand, he ran around it to hit a forehand (which he did reasonably well), and my partner was sitting 2 feet behind the center strap of the net and easily put the next ball away before the returner could even move to defend. The returner basically handed us that point.
Your defensive positioning options are just better if you just use the backhand. You won't be as tempted to go big and you won't have to sacrifice as much of your positioning. This is why I feel the better/more flexible return wing should defend the T serve and the weaker return wing defend the wide serve. It's easier to pull balls crosscourt with a weak wing than it is to pull a ball inside out with a weak wing. The former is a shot you should be used to hitting VERY often, the latter you almost never practice. If you're comfortable going inside out with either wing off of most balls you see, then you can play whichever side and whatever return strategy you want. But the smarter players realize T and body serves are the best in doubles since they get your partner involved more easily, As such, it would be best to align your returns to defend against that. If they play mostly wide, their net player will be taking more risks to poach early (exposes the alley, which many experienced players can easily hit to if you move early) and have to cover more ground to reach the ball if they stay honest.
Better positioning => able to reach more balls => able to get more balls back => force your opponents to hit more winners to beat you (either they start missing or they play patiently and you get to play tennis).
Good point, you have to be unpredictable, you have to concede that if the net player gets it right you might have to kiss the point goodbye, but dont donate it due to being spooked by the net player. Pick your shot (however late that might be) and commit fully to it.
Yeah, if they hit a winner, they hit a winner. It's still on them to end the point. Server has the advantage in tennis, just call it them playing well and doing what they should be doing. If you give them free balls all day, you don't test them. Maybe their volley is garbage, Maybe it breaks down after two or three shots, and it's not too hard to try and make one or two extra stabs at the ball to keep the point alive long enough for them to miss (especially if your partner is helping you out).
If you go for a great shot and miss, nobody gets to play tennis. If you hit a mediocre shot in, at least one more ball will be played and there is a chance that tennis will be played.