Even if you spend all day breaking that way, if it only goes in like 1-in-30 tries, then you have to admit there's some luck involved too. Kind of like how if you gave me enough tries at hitting the bullseye in darts blindfolded, I'd eventually hit it... but I can't claim it was "skill" even though I did it on purpose.
Let's say it really were a 100% controllable skilled shot. Then some pro works hard to figure it out and is able to do it consistently, sort of like making the 2nd ball in 10 ball. Say they get that 8 in the same pocket 70% of the time. Now how do you like it?
But, we both know 70% will never happen no matter how much you practice. Which illustrates the difference between adding "fake difficulty" to a game (aka luck) and "real difficulty".
Real difficulty can be influenced by lots of practice/skill.
With fake difficulty, the outcome just isn't influenced much (if at all) by these things.
It just happens.
The only reason we accept it, is because it happens rarely.