The Cobras still suffering side effects after successive generations. In Cobra Bargain, it's noted that as of Jin's (third) generation of Cobras, no one really knows what programming is in the nanocomputers, what reflexes and combat maneuvers they contain that aren't used anymore, and thus forgotten. Implying the Cobra Worlds lack the infrastructure and scientific base to go about refining the process and mitigating or eliminating the side effects, even if they wanted to. And as for the desire. . . the enhanced political and personal power Cobras wield may make many feel safer with them having what amounts to a built-in expiration date, and those who like having the Cobra double vote representing their political interests may like them having an incentive to retire from Super-Soldier work and go into politics.
