I am a Baha’i rather than a Muslim, but my religion shares with Islam a proscription on creating images of our founder. To my understanding, the point of this rule is to guard against idolatry. Worshipping idols is a common dodge human beings take when faced with religion - obsessing about the messenger is a good way to avoid facing up to the message. Making images won’t automatically cause this to happen, but I think it’s a useful measure to discourage this very human tendency.
A crucial point, however, is that you’re not very likely to fall into the trap of idolatry if you make an image of the founder of a religion you don’t personally believe in. Not making images is a rule for believers, and it doesn’t really make any sense to try to apply it to non-believers.
There was recently a bit of discussion surrounding the Wikipedia page about Baha’u'llah, the founder of the Baha’i Faith. It’s a web page likely to be viewed by many Baha’is, and as such we would like it not to have an actual picture of Baha’u'llah. On the other hand, the page is for everybody, and if you’re not a Baha’i you might reasonably expect to see a picture there, as you would on any other page about a historical figure. Baha’u'llah lived more recently than Muhammad, and photographs of him do exist. As you’ll see if you go to the page, a happy compromise has been reached where a picture has been linked to instead of being embedded in the page. You can see it if you follow the link, and Baha’is aren’t forced to look at it. It’s polite to Baha’is , and I appreciate the consideration.
The same consideration wasn’t shown by the Danish newspaper that published cartoons of Muhammad. I don’t know the motives of the people responsible, but it seems possible that it might have been intended deliberately to cause offence. If so, any Muslim would be well within their rights to write a letter to the editor requesting that it not be done again.
Anything more than that will always be counter-productive. A non-Muslim cannot do any harm whatsoever to Islam by publishing a picture of Muhammad, no matter how insulting. In fact, there is nothing a non-Muslim can make that can harm Islam. Islam can only be harmed by Muslims, just as Christianity can only be harmed by Christians, and the Baha’i Faith by Baha’is. No number of bad cartoons drawn by a non-Muslim can ever match the damage caused by a single violent act committed by a Muslim. That’s simply the responsibility you bear when you belong to a religion.