I think the issue was more that languages often used to have multiple implementations which differed and no real standard beyond the de facto (whichever was mos

I think the issue was more that languages often used to have multiple implementations which differed and no real standard beyond the de facto (whichever was most commonly used). You saw this with the variations of BASIC on the micro computers, the different Pascal and C compilers of the 70s and 80s etc. But even back then, languages without a compiler were still nothing more than an academic exercise which entertained a comparatively few of the overall engineers around at that time. So I don’t think much has changed in that regard aside the expectation that a language should now have a reference implementation. And even then that’s not always the case (eg Perl 6).