Finding the right balance usually requires, unfortunately, a very mature company with a policy of keeping talent happy and a strong R&D department (which requires a lot of income to maintain). The creators get to thrive in R&D while the maintainers get to thrive in working on very mature (and usually profitable) codebases.

I say unfortunately, since those companies tend to look like (and are) Oracle, IBM, Microsoft, etc. Oracle, in particular, has a policy that you can make any lateral move you want at almost any time; at the cost of pushing out your eligibility for a raise.

This kind of flexibility doesn't exist in most startups; I've personally been turned down for a lateral move within a startup because I "failed" a whiteboard interview. Startups also don't tend to attract the Maintainer personality since they are considered startups because they're creating something new.

I also think they have trouble with easily accepting lateral transfers because there's so much raw talent banging on the doors that it's appealing to bring in outside help on new projects. Especially since a transfer will be viewed as a loss of critical knowledge about the project that just switched into maintenance mode. What's missed is that the person who requested the transfer is probably going to leave anyways because of a the mismatch with their new job role and what they want to do.