Change my view: You should be able to change Ascendencies at a cost.

I mean guys...GGG doesn't even tell the player it's an irreversible choice in game...

Locking Ascendancy choices doesn’t make the decision more meaningful...it just punishes players for mistakes or lack of knowledge and runs counterpoint to experimentation.

Overall it's a net benefit for the player and GGG to provide a steep cost to respec into the other ascendency.