So it was all about PVP that bash got nerfed?

I think it was part PVP and part PvE because bash builds made both vet solo arenas pretty trivial once you figured out a system. But to be fair, that could be said for many builds. The same thing for PVP; a bash build was good enough to be competitive if you played it right, but there were a lot of builds that performed better and were more forgiving. I assume the 40k you are talking about comes from the power slam change? Because I ran a bash build that ran deadlands with jolting arms, and even when I got a crit with jolting proc'd and corrosive armor activated, I was hitting for under 15k. I also had golden jewelry with bash glyphs and over 33k resistance. So pretty much maxed out bash damage. A regular bash against a standard resistant (20k+) player hit for between 3-6k. I don't think that's a lot for a single target melee attack, even if you can make three attacks in a second because no one stands there and lets you hit them. A single Hot and some evasive movements were all it took to negate most of my damage. They should have nerfed power slam instead of nerfing all bash builds. Before the change to Power slam, it was not even close to OP in PVP; I even had people whisper to me that it was nice to die from something other than whips and jabs lol.

PvPers aren't responsible for this change it's 100% on the devs.
Bash builds in pvp were fine in Deadlands but then Zos decided to change power Slam to inherit bash damage amplifiers which is an issue in PvP.

Rather than tuning power Slam to be balanced Zos decided to slap bash in general by nerfing deadly bash.
This is just another case of the devs not admitting that their initial change was bad and therefore changing everything else before reverting the bad change.

Soooo, does Power Bash now trigger the Void Bash set from Vateshran?