Quote from Simon:
"Because we don’t expect anyone to use both PuTTY and PuTTYtel, so the all-in-one zip file contains the maximum set of programs that we expect any user to use together.
We always assumed that anyone who uses PuTTYtel should do this because they are not allowed cryptographic software in their jurisdiction, in which case they cannot use any other programs in the package anyway, so PuTTYtel will be the only thing they could legally download. (I suppose we could have a Plinktel view - Plink with SSH has been removed - but no one ever asked for it.)