It's all about how it's presented. Gems aren't presented as win buttons but rather as boosts to a particular aspect. When you add boosts together you're basically buying things outright but there's no button for "$65 max level barracks" (haven't played, won't be). This is important because it's more like "I have all these pieces except..." and you have this resource you started with and have received more of via normal gameplay that happens to solve the problem. I'm sure the amounts start low and slowly increase.
As for the hollow/bored, it's a competitive multiplayer game. Being the biggest dog in the neighborhood is always fun and once that's over it becomes you against the guy in the next neighborhood over who's also spending so it becomes not about spending money to win but rather spending money to compete.
This is a classic pay to win set of mechanics. It works when your audience either doesn't know how things work like the author or doesn't care (enthusiasts of the korean mmos that pioneered the model). I got pay2win burned–enjoyed the game, didn't recognize pay2win, basically did the same analysis as the article author, was sad–when companies in the US were initially exploring the space. I now check how the company is making money off the game before playing any F2P and convert microtransactions to dollars as part of the spending process.