Here's my hangup: I can't understand why one would start with a blogging platform, pound at it with various plugins and transform it into, say, a product/ecommerce website. It feels like starting with a shovel when you need a pick (or some other more applicable analogy).
That's the part I don't quite understand. Carrying all of that baggage to build something diametrically opposite what the original stated function of the software may have been.
On the funny end of the scale, I've seen five page static websites with a landing page, a few info pages and a form done with WP. Unbelievable. Are developers that lazy today that they throw WP at everything? Or is it easier at that level to charge X to do a WP site rather than charging the same for straight-up PHP/HTML/JS?