It doesn't have to be "much" of a factor, it just has to be a factor.
If no slop rules means the top 3 winners are Adam, Bob, and Charlie...
and slop rules means the top 3 winners are Adam, Charlie, Bob...
To some people that doesn't look like a big deal. But it's a big deal to Bob.
He lost money because of the rule. Maybe in the long run, over the course of many tournaments,
it evens out and Bob wins more money than Charlie over the years.
The problem is, pool doesn't have many high payout tournaments.
If slop costs you $5,000 in one event, there's no guarantee the 'rolls will even out'
and you'll win an extra $5,000 later in the year. You might just be shit out of luck.