Good question and the answer is really a combination of two things.
1st and foremost, lack of money. I left home very young or more accurately, I was an ass of a kid and got kicked out.
I was unemployed and living on $400.00/month unemployment ensurance. Given my rent was $400/month I was left to hustling to make money to even afford table time and to eat. I got by but the majority of the money games were in 8-ball/9-ball matches so you lose focus on the real game you want to play.
The next biggest issue was the lack of a proper circuit and that's still a huge issue in Canada. To properly progress from amateur to pro you must compete against progressively harder opponents. This is usually done via structured leagues where you progress up the rankings/divisions and get noticed. That time is when you have the opportunity to gain sponsors, funding and a few $ from events. That structure is non-existent in Canada. As I mentioned, just when my game was reaching the level where I felt I could be competetive, interest in tournaments hit an all time low here. Tournaments that previously attracted 64+ man fields started to struggle to find 16.
Pool halls got busy pulling out snooker tables and putting in little 8-ball tables rendering many halls that used to host good tournaments unusable as a tournament venue. I recall showing up for a pro-am event that had 38 odd players registered. When we showed and we found that the hall had removed all but 2 snooker tables.
Those of us who didn't travel hundreds of miles to attend immediately pulled out and those who were left wound up with a non-event. Virtually all the other good events went that way and interest was all but gone. No events, no money, no interest from the younger players.
The up and coming players gravitated away from snooker into the more lucrative 9 ball tournament circuit, further reducing interest in the sport. Televised coverage of professional events kept on for a bit but the broadcasting of the events got worse and worse. Within a year they were starting to interrupt century breaks for commercials and then come back in another frame saying what the clearence wound up being.
It's a real shame snooker has gone the way it has in Canada but at least it happened while I was young enough to recover and get on another career path.
Do I have regrets of what might have been? Yes but I was always realistic about the state of the game in Canada which tempered my expectations. I knew when I started to devote my time to the game it was in decline in Canada but I loved it and would've still done the same thing even if it was guaranteed that I could never go pro.
Love the game first, worry about making a living at it second.