That actually sounds like the normal experience pretty much everywhere outside highly in-demand fields. A poor performer will be sacked in a second, unless the demand greatly outstrips supply. Money-seekers are in the process of oversaturating the tech-talent market, so I wouldn't expect the favorable conditions to last for long.

Those aren't mutually exclusive. You can encourage employees to grow and get rid of people who aren't taking advantage of the resources to grow that you're making available.