Problem is, one reason why he's not making a living out of it is because the Powers of tennis have denied it from him. Challenger prize money has been largely stale for DECADES. By contrast, Grand Slam prize money has increased tenfold over last 25 years. This mean that absolute top is making more and more money, at the expense of rank & file players.
Telegraphic style, coz of repeating constantly -
the pros have doubled during the last 25 years.
Ivo Karlovic would play until 45yo if possible to make a living at Futures.
5 more years of Karlovic career means around 20 young guys struggling more.
No one would retire ever if they make a living off futures, they'd just win a round here and one there at the expense of younger talented guys losing motivation.
Tenfold the money going to TAs for development of good juniors.
We have to chose - either we give the money to develop young players through the TAs, or we cut the TAs, give the money to old vultures and have the pro tour reduced to 500 guys in 10 years, then we can kiss the sport goodbye after 5 more.