As I've said, we made the turret changes specifically for the pro scene (and maybe really high elo ranked), because lane swapping really only happened at that level.
Let's put aside for a moment whether or not you believe that lane swaps are good for League. We concluded that they weren't good, that they were making the viewing experience for League more boring, and that at the extreme case, maybe it would cause some viewers to lose interest in pro League at the crescendo of the season.
We also discussed the changes with pros and coaches and backed off of some of the ones that scared those guys the most. (I wasn't personally in those discussions, so I can't tell you which team said what specifically).
So at a high level, there are two competing interests here. Making changes to the game can be hard on pros as they have to re-adapt to things they had already learned. On the other hand, making changes to the game that keep the games exciting and viewers interested is also in the pro long-term interest.
Ideally we would have made the turret changes a patch or two earlier, but we wanted to make sure there was broad alignment between the LoL team, the esports team, and the players.
