Turn top half of genetics into cloning.

[BaneOfGiygas]

If you don't want the risk of being a borg, don't get killed.

I don't know what kind of game you're thinking of, but on Space Station 13, you don't just "not get killed". It doesn't work like that. Shit happens and people die, and even the best of us fall victim to a well-placed bullet or a toolbox or whatever the hell happens. If it was as simple as "not getting killed", the cloners wouldn't even need to exist because we'd all be deities of robustness.

Basically the sole job roboticists have (unlike geneticists) is to revive people

Technically speaking, the roboticist has the secondary job of making med/fire/floor/secbots to distribute across the station as needed, though this is just about never needed in any capacity. However, your point is definitely valid in that roboticists have a distinct lack of shit to do.

the borgs are almost entirely self-sufficient

Self-sufficient in the sense that they can exist and do things independently? Sure, that's technically correct. But you seem to be missing the very important details, like how cyborgs can't pick shit up, can't interact with most shit, are at the absolute mercy of (most) crew orders and/or the AI laws, and are SEVERELY limited in the ways that they can exert independence when the crew is telling them to do this, that, or the other. Some players are fine with this, but the vast majority of them would rather be a human being with working hands and the ability to toolbox a bitch if need be instead of being a robotic servant.

I don't see how it's fair to completely ruin any chance robotics has at ever doing their job just because you'd rather be cloned than borged.

This seems to suggest that everyone's a bunch of mustache-twirling cartoon villains out to ruin the lives of those poor little roboticists, which is sure as hell not the case. If a player finds the idea of being turned over to the Roboticist such a terrible concept that they'd rather not be revived at all...that's not the player consciously taking a stab at the Roboticists, that's the player having an opinion that something is shitty. And if a helluva lot of people have the opinion that something is shitty, then maybe it actually IS shitty and something should be done to make it less shitty.

Basically what I'm saying is that Roboticists will get corpses once people actually like the idea of playing as a cyborg.