I mean good point, but if I'm just using bash as a shell and not writing a script, I'm probably first previewing the contents of a file with cat anyway, and recalling the last command and appending a | grep <pattern> to it is less keystrokes than re-writing the last command into grep <pattern> <file>. Especially if you're playing around with the pattern and trying to get it right, it's nice to have the pattern at the end of the line.