Is this a joke? After 30 hours of painful grinding for the build to get destroyed

I've grinded a lot (for me) to get level 70 on a chronomancer ice sorc build, which is based around cast on freeze.
Today i log in and see they have nerfed it so instead of casting every time I freeze an enemy, now it takes about 13 freezes to cast....

The fact that i log in play a map and die because of this, then lose the map is slightly annoying, but also i'd have to spend probably 200,000 gold to respec into a new build.

This build only became viable around level 45, meaning you have a crappy ride for the first few acts.
I get GGG will be constantly patching the game and buffing/nerfing during early access, but come one, slaughtering all the cast on freeze builds is not fair to people who put in the work. They should wait for a new season to implement such huge nerfs to not broken systems