> You don't have to buy anything and the experience is just fine.
As implied by the earlier commenters, that's obviously not the case.
> It's just the option is there if you want to go faster.
It's only an "option" because they crippled the game in the first place.
> Also, it's a free game. If they charged $60, then I'd get your point. But the game is based on a "Freemium" model like tons of other software.
And thus, freemium is inherently abusive. But even then, there are more acceptable ways to do it.
For example, look at how Smite does this: free to download, you can pick between grinding/microtransactions to unlock each character individually, or pay $30 to unlock everything in one go and effectively go back to what the game should have been from the start. Cosmetics are still paywalled, but at least there are no more microtransactions that have any effect on gameplay.
I'm not against paying for games. I'm against constantly being hounded to pay for the same thing over and over again.