actually, he doesn't make any assertions that Python is more flexible than Perl (which would be rather doubtful), only that it is more readable (which, as a perlista, I'm sad to say is probably true).
but I also get the sense that this is the first time he's seriously delved into a dynamic programming language. much of what he's saying about Python is exactly what bioinformaticists were saying about Perl in the late 90s / early naughts.
The thing about readability of Perl vs. Python ... I dunno. I don't think it's the syntax itself that causes Perl to have some readability issues. Stuff like `$foo =~ s/bar/baz/g` or `join '-', split( q{ }, $a_str)` is very readable.
Context and corner cases maybe makes readability suffer. For example, what does `m///g` do in scalar vs. list context? I don't recall.
you might say that Perl's lack of (obvious, first-pass) readability is a two-headed dog from hell:
- it's a (very) good thing, in that there's -a- -lot- of expressive power hiding in those corner cases (esp list v. scalar context). in fact perl is nearly unique in the degree to which it embraces, rather than seeks to quash the potential for nuance and flexibility to be found in the various eddies and whirlpools that lie "between" non-whitespace elements of code. this is something that goes to the deepest intellectual roots of the language (to be more like the way the human brain thinks, rather than the way machines think).
- it's a (very) bad thing, in that the same "power" for expressiveness just represents little more than an endless stream of banana peels to most first time users (understandably sending many of them running into the arms of the other major dynamic programming languages). and that it just makes it too damn easy to write (barely) functional, pothole-laden frontline scripts (such that Perl is partly responsible for "scripting" being such a dirty word, in many quarters).
another aspect people don't like to talk about its nearly coprophilic fondness for not just nuanced and context-sensitive, but intentionally obtuse syntax (the impossible to remember "special" variables such as $[, $;, $' etc being probably the worst examples).
this also (sadly) has a lot to do with the community's deference to the aesthetics of its original authors (and is also plenty understandable, given the extent to which unabashed ugliness -- as personified by makefiles, shell languages and macro-laden C and C++ -- ruled the day at the time).
unfortunately it also blinds a lot of Perl folk to the fact that beloved muse just happens to look awful darn cluttery (or worse) to many reasonably intelligent people who come from more "modern" programming backgrounds (or who at least came onto the scene comparatively recently).
but I also get the sense that this is the first time he's seriously delved into a dynamic programming language. much of what he's saying about Python is exactly what bioinformaticists were saying about Perl in the late 90s / early naughts.