New Dragon Article: Ecology of the Fire Archon

[Lackhand]

Because Hack&Slay is a valid and supported playstyle, and non-combat monsters are wasted space for that group. Why make a monster that only works outside of combat if you can make it work for both sides?

Plus, non-combat monsters don't really need any combat stats.

This. I've said it before, I'll say it again: What I'd really like to see, ideally in the DMG (which isn't going to happen!) but optionally in another book, are notes on noncombat statistics of the world of D&D.

Things like the old gem- and herb- tables from the 1st edition DMG, but also the properties of purple worm digestive juices, the suite of abilities a Marilith can manifest that aren't applicable in combat (since they'd clutter up the stat-block) but which should still be available to them, and the suite of abilities a variety of otherwise unoffensive critters have that doesn't immediately imply they should have a full statblock treatment. We don't have stat blocks for cobblers, smiths, or barristers in the MM; why should we have them for helpful pixies or benevolent (but non-combative!) angels?