To be fair; the real comparisons they're making are to things like Ruby, Rust, Python, etc. These are all languages that have done extraordinary jobs at evangelism and at setting up communities that are structured to have friendly, non-adversarial cultures. It's not an accident that these languages have become obscenely popular.

The "design" in terms of how it looks is, as you say, irrelevant. The "design" in terms of what information is conveyed, is deeply flawed in the sense that it's excellent for anyone who's already using the compiler - and completely useless for someone swinging by wondering about getting into Pascal in 2021. I.e. "preaching to the choir", as they say.

A fair amount of why websites started to also look different over time, is they structurally altered themselves to convey additional information. For example, a lot of programming language/compiler sites have images at the top now giving "strangers" a quick glimpse at the syntax.

It's all about crafting your website so it's useful to complete strangers, rather than only useful to the existing in-crowd.