The specific example cited

while(<>){ $h{$_}++ && ... }

is quite understandable to anyone who has used Perl for more than a few weeks. Its a common pattern. Complaining about this, which is, for the uninitiated, looping over reading each line from STDIN until EOF, incrementing a hash variable indexed by each line, etc.

This is a very common pattern in perl. Draw your own conclusion as to whether complaining about idiomatic language from a "skilled practitioner" is something one should take without a grain or two of salt.

And of course, being Perl, there are many ... many ... ways to accomplish the same task. Leveraging CPAN modules. I'd leave discovering some of the as an exercise for the reader.