This is an interesting topic because I belong to a course where new back tees have been built in the past 5 years, primarily by lengthening what were previously the longer par 4's. For example, one hole that was previously 425 is now 455 from the blue tees. The differential between the whites and blues has gone from 250 to at about 450 yards.
One consequence is that fewer people play the blues. Even some low single digit handicappers prefer the whites, probably because the longer par 4's have become 3-shot holes for many players.
This is unfortunate because some of the holes that haven't been lengthened are more interesting from the blue tees. For example, one of our par 4's is 385 yards from the blues with a slight dogleg right and trouble on the left, creating a challenging tee shot. From the whites, it's a straight away 355 yard hole where any shot shape can work off the tee. Boring! There are other examples.
While I enjoy the new blues tees, I think some players would be interested in a course set up like the old blues.