Guild Wars 2

Here are my speculations.

Nerfing Ranger means:

1. Bots die faster, kill more slowly >> Less income of materials poured into the trading post >> higher prices for materials that are needed to rush-level Characters and materials that are needed for legendaries >> People have to grind more, thus, play more to make up for the loss or buy gems >> Players keep playing and money keeps flowing for Anet

2. People switch to other classes >> Have to level up again >> New gear, new needed playtime, new money you have to spend, and so on >>

3. Less People play this class >> Less need to fix it >> Able to focus on much played classes >> Greater amount of people that are happy with the patch

Fact that backs up 1: They have so called “economy analysts” that look on data and guess how it would affect the trading post. They sure as hell wont tell that it’s a good idea to buff bots.
Backup for 2: Reading the Forums, for the majority (PvE) everyone switches to Warrior and Guardian.
Backup for 3: Warrior gets buff after buff, pleasing nearly everyone who plays PvE at this point.

Did i forget any point that prevents them from doing so?

Your idea is competent. Its possible but not the only reason of all our disappointment.