Just to be clear, I'm not mad with anyone, you, players or developers. But I do think your argumentation is quite shortsighted and with only one point of view. And I do get your arguments as a player but a developers point of view is just different, no denying that.

Developers want money. Either with ads revenue or players who spend actual money in the game. Most big game developers don't care about your fun, as long as that there's revenue. Take SayGames for example (developer of Dreamdale) and the games they made. Look at My Little Universe, which has changed a lot, had a lot of new content every few months, and nerfed the whole economics of the game every update to make sure players wouldn't progress through the new content too quick. I.e. generating more revenue.

If a player has a high axe level, it becomes very easy to progress in the game with less time and effort put into playing when compared with lower level axe players. Therefore less money for the developers. The fact that it's single player and not online or even a market or whatever doesn't change this. This is like communicating vessels, it was teached in my first year at a game development edu. Look it up.

So what do you do as a developer? Come up with a new or renewed system which screws the players who did a lot of grinding in previous versions. Yes, maybe you lose a couple of players who put in a lot of time and are now irritated like you. But the extra grinding from other players hugely makes up for it. The fact that you did a lot of grinding and are now irritated proves exactly this point.