Agreed, this is one the primary principles of the Unix Philosophy [1].

I was curious how performance would be impacted, and for a large file `grep` may not be so useless.

    $ du -h /tmp/file.json  
    161M /tmp/file.json

    $ time awk -F: '/"id"/ { print $1 }' /tmp/file.json >/dev/null

    real 0m17.810s
    user 0m17.690s
    sys 0m0.083s

    $ time (grep '"id"' /tmp/file.json | awk -F: '{ print $1 }' >/dev/null)

    real 0m3.617s
    user 0m3.641s
    sys 0m0.037s

While pushing the filter into AWK is a bit easier on the eyes, it appears there is an incurred performance cost.

[1] http://www.catb.org/~esr/writings/taoup/html/ch01s06.html