ennuikiller:

Since the OP waived the security argument, I don't think that the AM was referring to security problems. Just the normal problems of differing shells doing different string munging before executing stuff is hairy enough. Depending on the shell, you'll have a different sequence of flaming hoops to leap through to ensure that your quotes, ampersands, exclamation marks, question marks, asterisks, etc. make it to the command rather than being intercepted and interpreted by a shell.

If you don't know which shell your user is going to use, it can be challenging to come up with an appropriate string to put within your backticks.

...roboticus

Update: ...and then after hitting the "create" button, I see the "security risk" in parens in the AM post. Sorry ennuikiller...