Nothing Islamic should be established as an acceptable basis for anything. Islam is a criminal enterprise based on forced belief, theft, rape, pedophilia, homosexuality, murder, and bestiality. It is one of the greatest enemies of humanity in history and based on the ranting of a goat poking lunatic. Islam is the handiwork of hell.
Why should the Gregorian calendar be changed? It has already been refined from the Julian calendar. The Islamic calendar contains 12 months with 354 days. It is used to date events in Muslim countries. If you look at some Western calendars, you'll find special or holy days of Islam listed, just as Christian holidays and holidays of other faiths are listed. It is not a question of which calendar is better, rather it is about inclusiveness, and making sure that the faiths of all peoples are represented and respected.
I do not believe that the Islamic calendar is a better method for counting years. I do not believe this mainly, for the pure fact that swapping over to a completely different method could end in catastrophe. We as Americans do not even know how to swap from inches to meters, how would implementing a whole new calendar work? I do not think it is a good idea.
At this point, why even both changing the way years are counter? Chronicling the passage of time is already arbitrary in the first place, so making it more "efficient" only serves to confuse everyone for no reason. We have a pretty reasonable system with no flaws, and while others work, possbility even better, there's little reason to make the effort to switch.
There are many calendars in use today, other than the widely-recognized Gregorian calendar. The Islamic calendar is one of a handful in the minority, and some may argue that the Islamic calendar is a better method for counting years. Ultimately, though, a calendar is simply a way to keep track of time; once you are used to a particular method, learning another may take too much time or too much bother to be worthwhile. For those currently using the Islamic calendar, it may seem to be the best method of counting years; those using the Chinese calendar may beg to differ. Certainly those using the Gregorian calendar also think their own method is best.