Both opinions go hand in hand, in fact. Julia allows packages to interoperate in a way most other mainstream languages simply don't, due to the combination of

Both opinions go hand in hand, in fact. Julia allows packages to interoperate in a way most other mainstream languages simply don't, due to the combination of its multiple dispatch and the type hierarchy. The fact that the language allows this interoperability to such level is very useful and empowering. But making proper use of this interoperablity means writing careful generic code that doesn't make narrow assumptions based only on currently known uses of it. Different parts of the ecosystem do this with different degress of care and success, with newer ones being better at it as lessons are learned and implemented. Yuri happened to work on parts of the ecosystem that were not-so-new, and made combinations that hadn't been commonly attempted. That doesn't mean that these weren't issues that need fixing and preventing in the future, for sure. But hitting bugs of this severity often isn't the typical experience for the average user - if it was, Julia would hardly have as many users, much less ones like NASA.