Are they slaves/indentured servants to Quake? I wonder, because the rest of the monsters seem to be undead or from the Elder world, whereas the ogres seem to have a looser tie to Quake.

I know there was some lore in Nehahra regarding the ogres, but I can't remember most of it.

I feel that they're being controlled by the stronger enemies, sort of like the alien slaves in Half Life.

What are your thought? 

So the deal is that some people within id wanted to make a fps fantasy themes, very much like the RPGs they were playing at the time, but they ran out of time and had to release what they had.

The ogre is probably a remnant of that. 

Before time the Elder Ogres were savage medieval warriours, that had nothing to do with guns and belong in earlier centuries. They were far more on the corner of the magic, that HellKnight attend. They were relative weak in weapons, but commenly strong shielded with their axes.

As the armour of the time quakers brought other skills like shells and nails, the ogres obtained these stronger weapons and became smaller. Guarded with their machine saws and grenades they've become a strange relick from elder time.

They lack technical skill and since they lost their shield they only worry about grenades and cells. 

Ogres are creatures of chaos whose lack-of-purposeness is closely aligned with Shub-Niggurath's nihilistic plot to overthrow all life. 

The ogre is iconic. It is one of the bread-and-butter, heart-and-soul enemies in Quake.

I believe Madfox is onto something.. although I think hammers and not axes makes more sense. They seem to be the engineers in the Quake realm. Ever resourceful, stealing the weapons of their enemies, smithing their own. 

first time i saw an ohre i thought he was csrrying a hammer
with his shirt he looks like a blacksmith 

At one point the Ogres had horns and I read somewhere that their grenade launcher was a nailgun unless I'm remembering wrong. Which probably explains the nailgun Ogres in some mods.

It's probably not a stretch to imagine that they had axes instead of chainsaws at another point. 

Din: See John Romero's own Twitter

R00k: The Ogre is clearly inspired by Leatherface from the Texas Chainsaw Massacre movie series. His grenade launcher is even shaped like a hammer which is the second main weapon that Leatherface uses. Source

So, at some points during the development, the ogre had:
- horns
- shield
- axe
- hammer
- nailgun
- grenade launcher

And the game manual also mentions him carrying a sack of grenades. 

sack = backpack that the ogre drops, I guess 

IIRC, the player's Axe weapon comes from an earlier Ogre model. Probably that's why it's so gritty and covered in blood unlike the other weapons.

Also, the Ogre is still holding a nailgun in his final model. That tiny weapon is way too small to fit even a single grenade, much less launch it. They must've switched fron nails to grenades because dodging nails is rather hard and would feel too much like hitscan.