I think it's highly inappropriate for a dealer to disparage on-line sellers. That sure wouldn't fly on any other forum I know of. And they aren't the space shuttle. Most maintenance is fairly easy. If you need your hand held and told what a wonderful bike you have and you made such an excellent choice , I guess only consider a LBS.
I don't see it this way and I say that as someone that built their own.
I understand a dealer getting frustrated at someone that bought online to save a few bucks then wanting a local dealer to take care of the issues that pop up. Obviously that does not affect you as you can take care of these issues yourself. Many can't or won't. I understand the dealer getting frustrated when someone that bought elsewhere wants their bike fixed ASAP, but they are going to get their customers bikes in and out first.
My daughter is fairly talented musically. We have bought all her instruments at the local music store because it is also where she takes lessons and it helps keep them in business. I do not know instruments very well. When something is not right we simply hand it to them and it's quickly fixed. Generally with no charge.