Miss making contact with 8-ball as loss of game is a brutal way to lose when your opponent still has 6-7 balls on the table as blockers.
Certainly makes you think twice about trying to run out early, unless you are confident you can complete the job.
Even non-intentionally one can still luck their way into putting you in a real bind, and intentionally they can really sew you up.
When I first retired and moved to where I'm at now, I frequented the local saloon with a couple of bar tables for a while. They had all the bar rules this thread is talking about. Call shot (all kisses, rail first on a table length bank, ...) versus call pocket.
Not long after I started playing there, I was down to the 8-ball and it was in the kitchen. Had to kick at it (my opponent had scratched on purpose!). I missed the 8 and he declared himself the winner and took control of the table. So, I put my marker up on the table and waited for my next turn at the table.
When I got up to play they asked me what the heck I was doing? The 8-ball was on the rail and two of my balls were close on both sides of it after the break. During my first 2 shots at the table I bunted 2 more of my balls in front of the 8-ball.
When my opponent went to shoot the 8-ball it was surrounded by 4 of my balls. I reminded him that he took the table from me for not hitting the 8-ball. He said that was not a rule here and that it was something he had heard about before in Canada (and all the regulars laughed).
I informed him that he had taken the table away from me in front of everyone using that rule. So, that rule was valid for the night (between us) and I was going to take the table back from him with the same rule. He tried a scoop jump shot (legal there) and jumped the cue off the table -- loss of game. Everyone laughed again.