Why is Scorch being nerfed?

Because they want people to think it was OP, despite it actually being literally worthless.

Scorch is op because it is completely base damage. A tank at top lane or a support at bot lane was taking this rune to do a lot more damage than they should be. It's not just tanks at top, range top laners were taking it to completely overpower their early game. It's also op because it is in the same row as other less effective runes. Water walking and gathering storm are both weaker than scorch. Gathering storm will scale better, but only after 30 minutes I think.

Because poke is overpowered currently. Same reason for manaflow.

What others here have yet to mention is that Scorch sets itself apart from other damage runes with the fact that it deals Magic damage rather than adaptive damage. AD champions can bring it into lane and use it to apply magic damage to help mitigate the armor of their enemies.

For me this rune is only good before lvl 6, instead the new 20-60 i think a thing like 15-80 and a CD decrease with lvl would be better...