I've definitely met some extremely polite qatari men...but I've also been stared at by them and received a great deal of unwanted attention from them.
It's true that wearing an abaya or just dressing conservatively will reduce the harassment, but it certainly doesn't eliminate it.
Sometimes I get frustrated and feel like all the responsibility is pinned on the women and people aren't holding men responsible for their own actions. No matter what a woman is wearing, no man has the right to make her feel uncomfortable.