And they're trending up: http://trends.builtwith.com/shop/WooCommerce
It's low hanging fruit, not a lot of effort for decent return.
This actually happened to me. Low-hanging fruit is often a mirage when it comes to the CMS world.
Yes, it's for professionals. Hobbyists can always use some Haskell web framework.
Professionals can also use a Haskell web framework. Increasingly so for their day jobs, at least in my case.
Yep. One of the signs of a professional over a hobbyist is pragmatism in using his tools.
>Professionals can also use a Haskell web framework
Sure, but not by market demand. And they might also be making their clients a diservice by this choice (e.g. making the project difficult to maintain when he leaves etc).