Only if those folks think paying for any seat entitles them to an empty cabin or adjacent seat and those interlopers in their sight line are diminishing their experience. I'm sure you're not that sort of passenger, but there have been reports of snooty ones who object to a full FC cabin and one of those *unworthy upgraders* sitting next to them.

The transaction of paying for EC or a preferred seat is finished when the choice is made, so the price offered must have been worth the perceived benefit at the time. What Delta does to fill the other seats on the the flight are separate transactions not involving the first transaction.

With the proviso that they aren't competing for a scare resource I value, like Woodford.