ping is a very useful command. It lets me see if a host is up. If you block
ICMP ECHO/REPLY then I instead have to play the "Guess what service might be
listening" game. Or I assume your machine is down and might worry (because I
care). So please don't do it. I really don't see what you're trying to gain; it
strikes me as firewalling without actually thinking about it. Are you by chance
ignoring things like destination unreachable as well? And breaking PMTU
discovery? Well done you.