This all comes down to the marketing strategy, goals and preferences I guess.
In my opinion Shopify is good for easy and fast money. Means if you just want to sell a few items with facebook ads on an simple but professional looking theme, then Shopify is the way to go.
If you want to build an e-commerce empire, means many online shops, many items, lots of customization etc. and your marketing strategy is SEO or to build an brand (could take years), then WooCommerce is the way to go.
Last month I had to choose between Shopify and WooCommerce and decided for WooCommerce, because I already got lots of experience with Wordpress, also I want to run multiple stores and do mainly SEO.
Just imagine how much money I would have spend for the monthly fee of 5 Shopify shops doing SEO (which could take months to rank). Not a good deal for me. Then I prefer to buy domains ($10), a hosting I already got, SSL certificates and a decent theme. Saved me tons of money.
In the end it just depends on the users preferences and goals. For me Shopify wouldn't have been a smart choice.