To claim that "sandbox" games deserve p2p status doesn't sit well with me
Sandbox games give you the illusion that it's unlimited and full of possibilities. When in reality those games have the worst grind, the worst gameplays, and the worst update cycles you can think of.
The problem with sandbox games is that the devs take years to bring it to a point where it's playable. Those game start out barren, dull, and glitchy. It's years before you start having any fun in those games because it's a sandbox of grind which you need to build for months, to years.
In regular mmorpgs like B&S you're given a quality product. Now whether you get through it fast or not is another story. The gameplay in regular mmorpgs is top of the line, animations, core mechanics, design, art, community, and update cycles are consistent and progressive.
Regular mmorpgs grow and pile on content on a consistent basis where eventually the game world grows to a healthy size. The difference between this and a sandbox is that in a sandbox you're thrown it to grind. In regular mmorpgs (yes that's what I call "themepark" mmos) you're thrown in them to experience an rpg with others.
I would say a game that gives you quality content to enjoy (however fast you rush through it) deserves to be p2p more than a game which makes you grind and
makes you pay every month to grind.
And lastly, B&S isn't p2win. Buying something from the shop and selling in game has been done in so many mmorpgs already, it's not p2win if those things can be gotten in the game as well.