Rotgut quicksilver instead of magic quicksilver?

Why don't more ppl use Rotgut quicksilver instead of magic quicksilver flasks? I'm using it on my TS build and I like it. I get more flask charges generated
with all the crits I do and there seems to be more uptime. Also I dont have any trouble generating more frenzy charges. Is there some downside that I'm not seeing?

It's the frenzy charge generation for most builds, especially when bossing.

thanks for the reply