While I agree that the sex is the overriding factor for many, I will still argue that the domestic servitude and those little things done to please a dom are very important to many in the scene. I don't think most people here that are serious about bdsm are under the impression it's just about sex. Personally, I gain a lot from both...and think that sexual servitude and domestic servitude are equally challenging, just in different ways.
The whole creation of the term bdsm implies this connection of different elements. If a couple is primarily into D/s or SM, they'll use those terms. However, as this is a bdsm forum, it has to be expected that all parts of the equation will be discussed: bondage and discipline, dominance and submission, and sadomasochism.
Hence, all types of servitude and choices in training styles should be respected IMO. I'm also not trying to be inflammatory; I'm just suggesting that the domestic and sexual servitude are two parts of the same equation for many. However, I believe that purely domestic or purely sexual servitude are equally worthy as long as it makes the dom and sub happy and fulfilled.
eb