People are blaming the DRM because the DRM simply exists; all the breakpoint proves is that VMProtect does what it says it does (decode sections of the game in the VM). It doesn't however prove that the DRM causes the stutter or performance issues, for all we know that could be a bug in the game's engine itself.
Hopefully time and more data will tell us for sure either way. We aren't there yet, although no lack of proof will stop the tech media from reporting on it.