I think something that confuses the issue here is that while most applications are a great fit for monolithic Rails (or similar), the applications that many of us here seek out to work on are those that are larger (in scale or in functionality) and more complex. I'm not sure how you could check this, but I suspect that people working on bigger applications where SOA thrives are over-represented here. Most of the debate between "you're not gonna need that!" and "I have needed that!" just stems from people attempting to project their own experiences onto everyone.