> I’ll remain unimpressed by interoperability improvements to CL so long as the culture of “roll your own libraries!” remains in place.

How do you think those Java libraries got made? Java has also long had a culture of roll your own libraries -- and you had to, because the base language and standard library were quite deficient. (That's a snarky point, admittedly, but there are a lot of libraries in various languages that are just built-in functions in Lisp or Python or whatever, and there's a scale of effort there between built-in functions, built-in standard library, etc. that influences the pressure to make and share libraries. Like, I once wanted to get an approximate fraction, like Python's fractional's Fraction.limit_denominator, but in JS I had to bring in Google's Long.js and then steal a hundred lines of code from Python's implementation and elsewhere. There might be a library now.)

Where Java won out was copying Perl et al. of having a centralized place anyone could upload open source, and then having armies of programmers forced to use it who inevitably end up making and sharing libraries and frameworks to make their lives better and eventually a desirable place to be for lots of things. J2EE and the JCP/JSRs were also masterclass social innovations to improve the ecosystem and take over enterprise and allow groups to agree on specifications if not implementations. Lisp's version of that is still absent. At best there's functionality that implementations add beyond the ANSI spec, and differences papered over with trivial-blah libraries, and occasionally some informal lobbying will get a feature implemented with the same protocol across each active implementation (package-local nicknames coming to mind as a recent one). Of course this situation isn't that different to a lot of other language ecosystems.

CL got quicklisp, much too late, but it's here now and provides a baseline experience to beat if someone wanted to try like has happened in Java with ant/maven/ivy/gradle/etc. CL is then just missing hordes of programmers, and is unlikely to get them without either big company backing, many more small companies using it (this seems to be the way it's slowly been improving in popularity in the last several years), or an unexpectedly popular application domain (perhaps with accompanying hardware) where using it and its tools provides the clear best-in-class experience, or even the only experience, good or not, as is the case for many things involving other languages.

The culture now seems to be "check quicklisp, if it's not there, roll your own, and share to quicklisp". Maybe some more effort needs to be made on "try to collaborate and improve if something is on quicklisp and not quite what you want but close" rather than making something brand new, but collaboration exists on quite a few projects, and Java has lots of overlapping libraries too, it's not that big a problem. If Lispers lost any of their "roll your own" enthusiasm, the logical endpoint when something's not in the quicklisp set is to give up and search for a library in another language. And if it doesn't exist there either? Your only option is to program it yourself or pay someone.

It really seems like you just want CL to get the libraries and tooling you expect from the Java world, especially stuff mostly used by big companies with big deployments. And that's totally fair, Java's a great ecosystem despite annoyances with the language (which a big IDE helps paper over). I just think painting the lack of an equivalent ecosystem as a consequence of "roll your own libraries!" culture is mistaken.