I agree... but take a look at your vanilla friends' marriages. How many can you honestly say started as friends who became lovers vs. lovers who became friends (if they're friends at all.)

In my experience, those are few and far between.

So, in my opinion, you can make a successful D/s match if the chemistry is there without necessarily being friends first.

BTW - by my definition, a friend is FAR more than an acquaintance... more even, than an acquaintance with whom you hang out.