Companies are interested in keeping the risk of their operations to a minimum. Software Developers want to learn and hone their craft. (This is not true for all developers and I don't speak for them.)
These two motivations don't align well with each other. Learning requies failure and unpredicability; Neither of which is good for company. Also, if you have employees who like to learn and experiment, they are more likely to innovate. The knee jerk reaction to this might be, "Yes! We WANT our employees to innovate!" But the reality is that not all innovation is good. More often than not, innovation can lead to creating silos and requiring special skills for developers to operate the tools. Tools that are unique and idosyncratic. This is not in company's best interest, because they want the cogs (Developers) in their machine to be replaceable. This is not malicious intent on the company's part, it just means that in case you want to leave the job for greener pastures then the company shouldn't get crippled and be able to move on and work efficently.
~ 5th May, 2AM & 11:30 AM