Great suggestion, but I'd go for a middle ground: use long flags for the long tail, but short flags are fine for stuff that's very commonly used.

I think I'll continue to write these:

    grep -i
    rm -rf
    ln -s
    gzip -v
    sed -e

instead of:

    grep --ignore-case
    rm --recursive --force
    ln --symbolic
    gzip --verbose
    sed --expression

If you're working on shell scripts, you probably know certain short flags well enough that long flags just add clutter and don't improve readability.