I highly doubt they can reproduce, but if they were given sentience by the Traveler by way of imprinting Human behavior, it is possible they could have affectionate feelings towards another, reproduction be damned. If some people are wondering how that would be even possible, well, the answer is rather simple JSFM (Just Space F**King Magic)

You're right, they don't have the instinct, but they can still learn and adapt like a true AI. Still sad that no amount of knowledge can fix all their problems.

Its a valid question. Perhaps its because people want what they can't have. Being mechanical and sentient doesn't grant them immunity to things like greed for any logical reason I can think of. Companionship may be desired for the logical benefits of having a support network. Developing personal connections with others solidifies that network. Perhaps the personalities they have simply cause them to "feel" that way... cause space magic. On the other hand you may be completely correct. Maybe they don't give a damn. That makes them seem kind of scary and cold. I didn't think the offspring were really a thing, but I couldn't rule it out, and the situation was worthy of discussion (Also, I talked about the effect on their partner should they decide to be romantically exclusive. The only reason the Exo might give a damn is because they don't want to hurt their partner [knowing that the offspring idea is important to said partner]). Supposedly, the Exo aren't really beholden to programming (in the traditional sense), but of course I know you meant evolutionary pseudoprogramming, like instinct (or more aptly the root of instinct). I also feel like I should clarify that none of this is really a given. Its almost all a considering of possibilities, and the ramifications of those scenarios.

Disguised double post F**k yeah editing!