College coaches are doing it because they love the sport.
I know coaches on the east coast who are calling recruits at 1:00 AM because that is when it is good for the recruit on the west coast, then turn around and make a 8:00 AM call to another recruit from their office. Every college coach that I know is trying to juggle 5 or 6 recruits and getting inquiries from another 50 that they are not interested in. The better coaches do their homework on every player because just because he may not be interested in a certain player, that player may have a younger sibling that they may be interested in the fututre. The thought that coaches get a down time is pretty funny.
Everybody thinks that coaches do nothing all Summer.
Most tennis camps rim for 4 weeks in the Summer, that go from Sunday-Wednesday. Those are 15 hours a day from 7:00 AM to 10:00 PM. They take Thursdays off and then head off to see players play tournaments on Friday and Saturday and then head back Saturday night to get ready for the next group of campers.
Then comes the month of July, when they are finally allowed to call Seniors and talk to them once a week. Stupid NCAA rule but I don't want to get into that. There are National Opens, Regionals, Clay Courts and Zonals thrown in there. I think that is enough said.
Then comes August. The supernationals and finalizing the team's Spring schedule for the upcoming year. Making sure all your current players are healthy and setting up official visits for September.
In the mean time the coaches have to stay fit, maintain their tennis skills, keep a marriage going, spend time with their kids and figure out a time to take vacation with their families. Why don't the families go with them to the tournaments? One reason is because thanks to our legal system, once a coach leaves on recruiting visit it constitues as a work situation. That means that the company they work for is responsible for anybody in the car. Let's just say the coach pays for the trip on his own and it is an actual vacation and he is just going to stop in and see a couple of matches. How many spouses are going to be that understanding when a routine 1.5 hour match turns into a 3 hour marathon match? All while the kids are waiting to go to the beach or the water park.