I sincerely believe that you, the user Havoc, are a responsible, sensible person who would handle client money as if you were operating a well-regulated financial services firm, even if such regulations weren't in place. However companies are not necessarily built that way - if they don't have to do follow some rule that could be considered a bit burdensome and (arguably?) not applicable to them, they likely won't. Why follow rules that might not apply to you, given that you are using a new-and-exciting instrument that you could credibly argue fall outside any existing regulations (and if doing so could permit you to speculate and make a bit of extra money)?
>it's no surprise newer crypto companies like Coinbase aren't particularly serious about keeping client money/assets separate.
I'd say the opposite. As crypto company I'd be expecting the regulator to be on my ass from day 1 above the pettiest things.