He brings up a good point. The anti-Muslims don't want to have to live under Shari'ah law, so they try to stop the spread of Islam. Should they have to live under Shari'ah law, they can't commit all their sins that they do every day.
To be totally fair, there's a lot under Shari'ah law that a lot of Western people - Muslim and non-Muslim - don't agree with or see as barbaric or cruel. What I think turns most people off or against Islam is that you can't get a free ride to heaven after saying a few simple words (like you can in Christianity).