Nobody can blame the guy for the design choices and naming conventions he made back then. The problem is that they still exist 20 years later when much of the worlds web infrastructure runs on PHP.

I'd have expected (hoped) that by the time of the last major release (v5.0) the chief PHP devs would have used that opportunity to to rename some of the core functions. By that point PHP's popularity was already established and the shortcomings of it known. Plus as there was already a major Zend rewrite under way, to me it seems a sensible time to throw in a few in a few niceties to beautify / simplify the APIs.

Perl -PHP's spiritual predecessor- managed to tidy itself up circa v5.8 and now, ironically, Perl is cleaner language to code in despite the jokes about it being executable line noise.