It's a strain because you depend on 7 other people to NOT run ahead with a different group and clear content. This screws the "static" because the person is either selfish or impatient, or is helping friends with content. Either way it screws people over in the end. Yeah it causes strain on friendships, groups, etc.

There is nothing wrong with SE letting players go into the turn and as soon as the turn is complete they are LOOT locked for the week. That doesn't change. This next part is the change...ALLOW players to renter the content without any loot rewards....it's revolutionary... So revolutionary DC Universe Online has been doing it for over a year now with their 8 man groups.

There is no reason for players to not be able to renter and play content solely to help others.