Raymond said:
ISTM the scope of argparse was never intended to capture all possible patterns for command line argument parsing.  Instead, it aimed at to address the common cases.

I say:
Sounds like another wet blanket argpment. Refer to the section "Why aren't getopt and optparse enough?" in the argparse PEP 389.  It is clearn that argparse was intended to implement more complex cases than could be easily implemented with the prior getopt and optparse. The concepts of variable numbers of arguments for an option, and of subcommonds, introduced initially in argparse, are far more complex than the enhancements proposed here.