Although CSS sucks more than a very sucky thing, and the text+markup idea barely makes sense in 2016, I can see how we got here - and how CSS needed to hit the classic "worse is better" sweet spot that allowed designers to play, and not just people who code.

But that was then. If someone invents a meta-protocol now and implements a meta-browser/meta-server for it, I'd expect cult/niche status at least.

I miss Gopher, in a rose-tinted glasses nostalgia-driven way

Scheme became the lingua franca of the web. Smug Array Weenies criticize Scheme for being “insufficiently APL-like”, while pure functional programmers criticize APL for being “insufficiently Haskell-like”. Legions of Scheme programmers write mutually unintelligible code, though still manage to criticize Haskell for being “insufficiently Lisp-like”. Prolog fails to catch on. Brenden Eich announces that continuations are considered harmful. C programmers maintain that continuations are the most reasonable way to handle errors in C. This happens in spite of C not having continuations. Douglas Crockford invents s-expressions as a data interchange format. Douglas Crockford writes “Scheme: The Good Parts”. Guy L. Steele sues Douglas Crockford for copying the Scheme standard. Hipsters begin using Node.Scheme to write their backends and are criticized for a nonsensical package management system and “using a web language on the server”. This happens in spite of Scheme having been a server language before it was used on the web. Microsoft invents a compiler with type inference and optional type annotations for Scheme. Facebook invents a compiler with type inference and optional type annotations for Scheme. GNU Guix is promptly ignored for “using a web scripting language for package management”. Facebook invents React, which uses an extensive set of macros to write HTML components in Scheme. This is criticized in spite of having been done a few hundred times before. Guy L. Steele angrily removes string-pad-left from the Scheme standard. This breaks many packages. Non-Scheme programmers laugh and wonder if Scheme programmers have forgotten how to program, suggesting that “proper design minimizes dependencies on the language standard”.

In all seriousness, Scheme would make a really good lingua franca.

Or maybe it's just the historical artifact that everybody claims to be, and if the PDP-10 supported a lisp environment, things would be different. But if I had to bet, I'd bet on metaprogramming not scaling.

I wonder if there really are mental types well-suited to Lisp and types ill-suited to it.

- Designers/developers will, as a general rule, always max-out the system; as long as the performance is at an acceptable level, the features and bloat will increase. If it becomes unacceptable, those features and bloat will be trimmed accordingly. Hence, no matter the underlying technology, performance will almost always hover around "barely acceptable". The difference would be how much "bang for the buck" we would get for that performance; presumably a "barely acceptable" page using CSS would be capable of more than a "barely acceptable" page using DSSSL, since DSSSL would exhaust the performance budget more quickly.

- Trying to dictate which stylistic elements can/cannot be used seems like a thankless task, since many will disagree and either come up with awkward workarounds or lobby to get their desired features included (which may or may not disrupt the coherence of the provided elements). Providing a full programming language is effectively pre-empting those workarounds, and giving the community control over the available elements (e.g. via libraries). This would lead to lots of awful code, but some good ideas would emerge and become widely adopted. Browsers might specialise their evaluators to speed up common usages, etc. Very similar to Javascript, polyfills, etc.

- CSS is, after all, "just" styling information, and is applied progressively on top of HTML. The document is still machine-readable, even if we might not be able to answer particular questions about its layout and visuals. It's conceivable that some people might, for example, obfuscate their document content, and re-assemble them using styles, e.g. to prevent crawling; that's more of a cultural/social issue than a technical one though, and that cat's already out of the bag with Javascript, single page apps, etc.

In any case, the current trend of working around CSS's limitations with Javascript is the worst of both worlds. At least we might attempt to evaluate DSSSL, to see what it might look like, whilst any attempts to evaluate Javascript will quickly run into barriers like side-effects (should we run AJAX calls? What should "alert" do? etc.)