"Who would risk building their company on a stack that you lose the license for if you do too well?" A similar question exists for laborers that need to invest

"Who would risk building their company on a stack that you lose the license for if you do too well?" A similar question exists for laborers that need to invest in learning tech stacks. Why spend time mastering something that certain companies are discouraged from using? Especially if a non-encumbered variant exists. Wouldn't it be more practical to learn tech that employers can easily use?