That is done so that existing scripts keep working. Nobody complains about the LLVM linker installing itself as /usr/bin/ld, or systemd providing /sbin/init, do they?
Actually, yes they did. The use of /sbin/init was something that came up during the Debian Hoo-Hah. The conclusion was that it should be a symbolic link, and that there should be distinct packages providing that link and providing the real executable program image file that it points to.
I am not really complaining, maybe unsatisfied of the direction it took and the consequences to other distributions without having a say.
But maybe people fancy the new PCP Dstat and accept their losses. In any case, money rules the world, Open Source ran by volunteers is dying and becomes less and less attractive.
The entire principle of a GNU based system is that everything is a reimplementation of original Unix tools with the same names but different provenances.