Why is there a need for a so called 'class update' ?

We had the adc-update, the juggernaut rework, the assassin rework and the tank rework. All of them were big patches with several reworks. And yes there are one or two good reworks that improoved the kit of the reworked champion (katarina, darius, talon, quinn) in each class update. But it feels like the other reworks are just for the sake of "at least we changed something, for the better or worse it doesn't matter". There was no need to rework zac, maokai, kog'maw, skarner or mordekaiser. Or at least if you really wanted to rework them riot, come up with an interesting idea first.

Not all that glitters is gold and I don't need a fancy looking huge update that reworks a whole class, if only 1 or 2 of the reworks are serious improovments of the champion. Of course there are also the itemchanges included into the class update. Everytime I read "We want the Item XXX to have a more unique character and that's why it will give you a ton of one stat and almost no other stats besides". There might be a need for the champions to have a character, but the items? Aside from the lethality items that took way too long to get balanced, I did not appreciate any of the item changes in the class updates.

Please riot. Rework the champions/items that need a rework but don't add tons of other changes for the sake of selling it as a huge update. And when you rework only one thing you can also add a beautiful event like the bilgewater thing to get the community hyped.