An observation on the state of full stack development and they way our brains tend to be wired.
One reason, as my developer friend pointed out, may be in the fact that two groups (HTML/CSS, JS) are examples of different paradigms: declarative and imperative. Imperative is focused on how we want to do something, where declarative says what we want to do. The two paradigms often (not always) correspond with how our individual brains are generally wired.
I have met very few developers who have the title “full stack” that are truly good at the declarative and imperative to the point of mastery. Many of my colleagues share the same observation. One end of the stack usually has to give, and in my anecdotal experience, the side that tends to suffer is the all-important HTML/CSS side. This is sometimes because the two are often looked down upon since they are, in fact, declarative. But remember, without HTML, we wouldn’t even have a web!
It may be time to once again swing the pendulum back from “full stack”, and embrace and give targeted roles to those who have strengths in a particular paradigm. I think there is a ready and waiting market of designers who are eager to take on this front of the front end, and leave the programming to those who really know what they are doing.