I usually quit playing if I am playing someone slow. Gambling or not.
And in all honesty, slow play ruins the game for tv matches. The general audience does not want to see someone poking around the table. I fall a sleep watching people like Souquet play. And I am not even one of a general audience, having played and loved the game since about 8 or 9 years old.
And tv and commercialization is where it is at unfortunately. It pays the bills for the sport. It is one of a few reasons pool has not taken off like Golf and many other sports. Another reason is bad management of the sport.
If the game had more colorful players like the Sigels, Stricklands, it would make for much better entertainment for the general audience.
I remember one time (guessing mid 80s to early 90s) Earl was playing another colorful character at Brass Tap Billiards in Raleigh, NC called Jumpin Joe. Now that was an enjoyable match for the general audience to watch lol... Though Earl went a little overboard.... And the people there ate that stuff up, loved it.