Riot Balancing. Why is Morgana being nerfed and whats the point of it.

Can someone in the know explain to me how Riot balances anything because I'm actually quite confused and it seems the balance team just muck about with things randomly to maybe justify their job.

Champions that almost noone complains about and abilities that noone complains about and have any issues with get nerfed while blatantly overpowered things just get ignored for ages.

Tormented Soil (W) damage lowered to [16/32/48/64/80 to 24/46/72/96/120] from [24/38/52/66/80 to 36/57/78/99/120]

Why on earth is Morgana's Tormented soil being nerfed and for really small random amounts? How many times have you stood in Tormented soil at level 1 and thought. HOLY SHIT THAT'S BLATANTLY OP, RITO PLZ! Morgana has a 51% winrate and the only thing people really complain about her is the length of her Q which is a slow moving skill shot so it isn't that easy to land.

Hecarim Rampage (Q) mana cost increased to 32/34/36/38/40 from 20/23/25/29/32 Rampage (Q) damage penalty against monsteres removed (was 66%)

Damage vs monsters has been increased b y 50% but mana costs increased at low levels by over 50% are you serious? After you already nerfed his health and mana regen is this even a buff to Hecarim jungle? Or is it a 'Veigar Buff'.

Bot of these champs have winrates between 50 and 51%, but champs with much more obnoxious kits and ridiculous win rates get ignored, or get meaningless nerfs that have near zero effect on their win rate.

It is nonsense like this that leads to champions being gutted and then having to be rebuffed months down the line, like Akali who was ridiculously overnerfed. This pointless balance and see-saw balancing points to a balance team that has no idea what they are doing, or is the a genius to their methods that I don't yet grasp?

And yes, I'm salty because both of my mains are being nerfed