I think people seem to still be talking about a number of different things and somehow considering them all "line cutting". So let's take WDW out of it entirely and put the examples into a different setting.
1. I go into the grocery store to pick up a few things. There is a 45 minute wait to be served at a check out. I leave my "husband" (or whoever) to wait in line while I pick up my few things. I return to the line and wait to get served. This is NOT line cutting.
2. I go to the grocery store to pick up a few things. There is a 45 minute wait to be served at a check out. I pick up the things and get into the line. After I've been waiting for 25 minutes, I realise that I've forgotten to pick up the milk. I leave my "husband" (or whoever) in the queue and go and pick up the milk. I return to the queue and get served. Again, this is NOT line cutting. Would someone actually leave the line entirely and wait another 45 minutes, after they've already been waiting a substantial amount of time?
3. I go to the grocery store to pick up a few things. There is a 45 minute wait to get served at a check out. I go and pick up my items. When I get to the check out, I push past the 100 people in front of me to get to the front of the line to be served first. This is line cutting!!!!

I guess for me, I'm not prepared to let other people
ruin my holiday. I'll never see them again, they've possibly added 30 seconds to my wait time and usually I'm so busy in the line chatting, looking at photos we had taken earlier, planning our next attraction, I don't even really notice, let alone care! I'm sorry that people feel the need to act as CM's and physically stop people from getting past them.

Is it really THAT important that you get on a ride 30 seconds faster?