Key exchange is done for speed (symmetric key crypto is way faster than public key) and forward secrecy. It’s not done because RSA is flawed per se. We use DH instead of e.g. ElGamal encryption for the same reasons.
Yeah it's not so much of a flaw of RSA, but encrypting pure text with it for example is more complicated (and has more caveats with padding, etc) than just encrypting a fixed amount of bytes
> Getting young engineers on the platform for free will pay off handsomely when they join a team and automatically assume Github is their code storage tool of choice.
Not everyone looking to have a repo today and joining a team tomorrow where it will pay off for Github is a student. Being able to pay doesn't mean the same as willing to do so, particularly if they've not used github yet and have no idea if it will be worthwhile.