First and foremost it is marketed in a huge way (can you say "promoted to the max"). At one time snooker was almost dead, and Barry took over. Promoted it in a way that got people insterested and excited.
Second there is a governing body that oversees all of the players to make sure they are not dumping and fixing matches. You get caught fixing, your banned.
Third the gambling institutions are in many cases, the main sponsor of the events so there are big bucks involved.
Fourth it is considered a "gentelmans' game". In other words, they there no fixes, they call fouls on themselves (when the ref didn't see it), they don't talks shit to their opponents when it's their turn, they don't piss and moan when palying, well I could go on but you get the idea. There is a lot of honesty in the game. You get a ton of respect from most folks for honesty.
That's my 2 cents.
That is why I watch it on stream, or utube it after the match is over (making sure I don't read much so I don't know the outcome). These guys and gals that play the game are fist class and honest. That is why I watch it.