Riot - Why do you hate turrets so much?

I've posted thoughts about the turrets before but I'm going to do it again in its own topic. Why do you continually hit turrets with more and more nerfs? I know nothing has changed in the last patch but for a while now any change to the turrets has just been to make them even more useless than they already are. What was so bad about mid lane that it got the hardest hit of all with losing the shield and then getting weaker in general than all other lane's turrets? Considering that once you break mid it opens up a massive portion of the map I would've thought you'd work it the opposite but you seem to want it smashed first.

The only time any turret is a real threat is before levels 6 - 8 and even then they can be abused earlier by simply walking slightly out of range to drop aggro and switch it to a teammate or incoming minion wave. If that isn't bad enough then the time they take to switch to another target is far too long. I'm not asking for them to somehow intercept the keyboard presses of players and nuke them before their commands even reach their champion but they really are quite pathetic. As it stands I don't think the game would change all that much if all non-inhibitor turrets just blew up at the 15 minute mark. Considering even squishy champions can take at least one or two tower shots without a lot of worry should be a big cause for concern but it isn't.

I understand the need to be able to push and force a turret down but it has to be harder than it is right now. Why not, as a quick thought, throw something like the mastery "Legendary Guardian" on in a buffed form? That way a turret will take longer if a team wants to force it down in numbers and make them really decide if they want to take it early and commit to it. There are so many other ways you must know to adjust them but they really do need it unless your intention is to have all games finish so fast that a fair few champions will be pointless to play. There are some that will take at least 30 minutes to be of any worth in a team fight and games are finishing quicker than even before. I'd really love to hear Riot's stance on why they hate turrets so much but doubt I will.