Your experience with SOAP is vastly different than mine to the point where I almost laughed out loud at your anecdote about adding a new web service dependency in a few seconds. SOAP is inherently complex, and needlessly so in my opinion. I've got personal battle-scars from trying to make Apache Axis and .NET play nice with all the various WS-* extensions needed for our use case.

There are always going to be people who, for lack of time, effort, education, whatever, use simple tools wrong. That's not an argument against simplicity. It is a recurring and false hubris to think we can fully specify any system and be "done." In the real world the are always confounding factors that violate the assumptions and constraints of any system we design. When that happens, I vastly prefer the more adaptable, less codified, simple system.

The fact that even those people above can still get stuff done even when using the tools "incorrectly" is an argument for the simple approach, in my view.