The thing about Guts on Scarf is when is it really that useful?
Paralysis, you're ruined either way.
Poison? Possible, but there's no Tspikes presence in UU and switching into Toxic is still a good thing for Moxie heracross.
Burn? Legitimate, yes, but burns come from walls which Scarf Heracross isn't likely to switch into, plus Chandelure is more adept at taking a Will-o-wisp.
Sleep? IMO Sleep Talk is a better option on CB as it means anything Heracross uses will hit ludicrously hard, when with Scarf you lack some of the immediate power if you get stuck on the wrong attack.
Meanwhile, Moxie Heracross comes in on anything slower and in KO range and all but guarantees a +1 boost, or the threat switches and fall next time they come in to Spikes damage.
i was nobody
we're all a little bit strange, don't worry about it