Angela for the sake of survival of the species.
I don't give a damn about their species. OPINION INCOMING!
Ratchet will most likely not be having kids. Look at him, he just doesn't strike me as father/wife material. It would hinder the story and bring Ratchet into a world of restrictions, very unlike the universe IG have made.
As far as Lombaxes are concerned, I would like to use the case of inFamous vs Metal Gear to (for the first time ever) side with inFamous.
Cole died in inFamous 2, and he is NOT coming back. I respect Sucker Punch so much for this that I have marked Second Son as #2 on my 'must buy PS4 games' list.
In Metal Gear games everyone keeps coming back: Liquid Snake, the unkillable Ocelot, Grey Fox, Solid Snake, The Boss as an AI, and worst of all Big Boss. And after death they all have some sort of hidden legacy or message! I love the series, but the resurrections are ridiculous. Every unbelievable plot twist comes from the simple 'I can't believe he's alive'.
If you asked anyone with a good knowledge of these series they'd agree with me. MGS is my #1 all-time favorite series, but inFamous handles this particular thing better. The Lombaxes are the same, except they aren't dead.
Sure it would be amazing if Cole was alive, and we'd all be happy knowing it, but it also means you can't get as invested in the story, if someone dies you don't care. inFamous 2 had such an emotional impact on me I'd never have with Second Son if Cole was alive.
Ratchet & Clank suffers from a very bad issue here, I couldn't care less that Ratchet died in ACiT because it always goes: The good guys win, and the bad guys lose. Tools of Destruction had the strongest emotional impact at the time because Clank was taken away. The game is like a cartoon, killing characters is a bad idea for the kids, so stealing Clank was a brilliant idea. ACiT handeled the return of Clank nicely, but that eliminates any sadness for the good guys. Luckily we have Alister to feel sorry for, and he dies at the end. Bravo Insomniac, Azimuth had a good run, and died in a very suitable way. And with a race of allies and family members of Ratchet locked away in another dimension it adds to Ratchet being alone in the universe. Truly sad, and well established.
THIS IS WHERE MY OPINIONS REALLY START.
This leads Ratchet and Clank to have an ever stronger relationship, they've both experienced pain, but have each other, and that's all they feel they need. The duo have people important to them who are gone. Orvus, and Ratchet's family. But this brings them closer together, and solidifies their relationship, which without we wouldn't have the games. So really from the way I see it, bringing Orvus/Lombaxes back would be a very Metal Gear thing to do, and signifies to me that the series could be coming to a close, which I honestly don't want to see.
tl;dr: I don't want them to come back, because that would be like saying 'Cole didn't die', and weaken the strength of the games stories by losing our trust.