I stumbled on it going from DEC OSF/1 errr Compaq Tru64 errr HP Tru64... HP-UX 9.0x-10.2x and AIX v3.4.x/4.x.x
Just like mounting /usr read-only... noooo don't do that now.
same thing with /tmp not having executables... many things now "build stuff" in /tmp and run them from there for a second phase of building or compiling or linking
Perl is another one to have bad habits built-into it sometimes, but its ok its the LSB now taking full effect of the old guard stuff and making it no longer supported... get the BSDs and other such *NIXs in a tizzy. Personally, I am unhappy about it, but there is justification of it. /var has been changed as from a "state" filesystem to a "status" of many things including DBs and system management scripts with "on install" values saved in them... (like upon mysql removal... should the DBs also be removed?) and other various things.
Bleah. Blurring of lines. Hate it... fact of life now, old ways(very tested and tried and trued) are being supplanted by new ways that are much more touchy feely and not always well thought out.