I think my favourite weird-proc-on-utility is Summoner.
You can only use Searing Flash if you've used Searing Light. Sure, fine in most 4-to-8 man content if you're the only fixed summoner. The minute you've got 2+ summoners who might stagger their Searing Light (if they use braincells and coordinate that is) for further buff uptime you're desyncing a pretty potent DPS hit out of your opener and re-open down the line.

The hilarious thing is that it really couldn't be attributed to button bloat for that job because we have so many open slots on SMN hotbars due to it's simplification. It could've been it's own button procing off of something else entirely in the 1-2-3 rotation of gemshines.

Baneful on SCH could've been an upgrade to AoW easily - would've been like the good ol' Miasma II days.

It's.. certainly a Design Choice.