Nice read. There is a viable alternative that's been around for years. It's called Miva. Also SaaS, it's out-of-the-box and features many things Shopify users have to pay for. And anyone can learn and develop modules.
Miva has an app store as well, and many are free or one-time pay at lower cost. Plus, you can customize in-depth yourself, if you're so inclined.
In my experience, Shopify users running the same features as Miva users pay more than three times more.
Shopify has its advantages though, which include a broader third-party market for plugins and connectors, and POS system.