if the golem is the big bad guy, no. if it is there to be defeated then yes.
Someone said earlier that golems aren't generally important to the plot. But Adamantine Golems aren't your everyday golems, they're the source of a tyrant's power or the guards outside a Runelord's throne room. They're not just another speed bump meant to burn some resources on the way to a 4 encounter day, they're generally the ultimate or penultimate encounter of the campaign.
It's up to the GM, but as a player I would really be upset if we worked our way through 17 or 18 levels knowing that there's this big, huge challenge at the end, only to have it go down on the first round of combat thanks to Butterfly's Sting and something that costs the same as a +5 weapon. That's really anticlimactic. Now, if the last 6 levels of the campaign revolved around finding the "only weapon capable of defeating the golem," and that weapon happened to be a greater smiting mace, that's a different story. Or if I thought the golem was permanently destroyed and went on to face the final encounter while it regenerated from -<crit damage> behind me, that would be interesting. Or if I'm level 23 and adamantine golems are mooks, sure, one shotting them with a mace is fine; I've got bigger fish to fry.
Mechanically, Adamantine Golems can't even be destroyed directly by a Wish or Miracle, they have to be dropped to 0 HP before they can be destroyed by those or a vorpal weapon. It doesn't make much sense to me to make them susceptible to being permanently destroyed with one shot from full health.