This is a sweeping generalization. Not all support players are toxic, just like not all Marksmen are toxic.
When you're paired with somebody who might be toxic, you gotta find nicer ways to ask them to stop doing things. Here's a suggestion for dealing with any toxic teammates:
A good rule of thumb is to consider the verb tense when you talk to them.
- Past tense is often used for blame, so avoid this if you don't want them to trigger from what you say.
- Present tense is about values, it is the stuff of motive, you use this if you want to try to influence somebody's motives.
- Future tense is the stuff of decision making, it's also the most constructive. Future tense is great for getting people to think about how to solve problems, while the other tenses usually lead to arguments over who's fault something was or over what is the best way to do things.
It helps if you say, "I'm having trouble farming, can you help me out by doing ___ from now on?" Rather than, "Can you be careful? You're making my life harder." The difference is in the implied gains and losses. When you say the first thing, you are asking them to do something by taking an action. When you say the other thing you imply they have been doing something wrong, and you might be right! But pointing it out will just trigger people who feel defensive or toxic.
It is almost always more constructive to talk in terms of the future.