I can understand the motivation for the 'Top 2 Only' rule, but I'm personally not a fan due to the impact it can have on players during the SC tournaments.
IMO, any given competitive pinball event should be structured as to maximize players' motivation to win or to place as highly as possible. However, the 'Top 2' rule places a unique shadow over any player approaching the top ~4 that is not 100% sure that they would be able to attend the national event.
Do you continue to play your best knowing that you may end up essentially killing a spot in the nationals that someone else (probably a friend given that it's the SCS) would have been able to fill? Or maybe a trip to nationals isn't really in your budget but you end up going anyway because you feel pressured to take advantage of a opportunity that would be otherwise lost to all. I feel like that any rule that puts players into situations like that is fundamentally problematic.
This very dilemma was under active discussion throughout most of Ohio's SCS event and I think it sucks for anyone who ends up in that position.