What would you say is the special thing about this particular bit of knowledge that made you point it out? To be perfectly honest, it seems quite arbitrary to me.
I could say I'm surprised to see how many people don't know anything about the browser rendering pipeline and consequently produce badly performing interfaces. Someone else would complain about people's inability to do even the most basic Linux administration tasks.
But at the end of the day any single bit of knowledge doesn't say much about your general ability to be a developer. The term "web development" covers an extremely wide array of topics. Luckily, there are many wonderful pieces of software out there that abstract things away and allow you to produce a finished product even if you aren't an expert in everything involved.
I could say I'm surprised to see how many people don't know anything about the browser rendering pipeline and consequently produce badly performing interfaces. Someone else would complain about people's inability to do even the most basic Linux administration tasks.
But at the end of the day any single bit of knowledge doesn't say much about your general ability to be a developer. The term "web development" covers an extremely wide array of topics. Luckily, there are many wonderful pieces of software out there that abstract things away and allow you to produce a finished product even if you aren't an expert in everything involved.