I generally attributed the discrimination to be more about dev culture than tech skills, whereas the enterprise dev maybe with a few years at a bank/insurance/pharma company might be too set in the traditionally slow pace in regulated industries or bureaucracies to adapt to the stereotype of a fast-paced startup. I never felt that startup leaders might actually think of them as lesser-skilled, and it wasn't discussed - the feedback on enterprise candidates would often be simply 'not a good fit' before an interview would even occur. I was always a bit uncomfortable with that reaction, as clearly there are many good enterprise devs of high quality regardless of what tools they use.