I would definitely put myself in this category. If I’m asked to post about something that I am opposed to, I turn it down, because I like the idea of blogging with integrity. This is not to say that a blogger cannot make a mistake and find out later down the line that the brand actually is not reputable.
For example, I write about and use natural products whenever I can find them. For that reason, it just doesn’t make sense for me to write about bathroom or rug cleaners that are mostly toxic, or snacks where you have to read through a long list of chemical ingredients just to find something natural hidden in there.
I am in quite a few blogger networks which also makes it easier to find the “rotten apples”, so to speak. If something about a brand is disreputable, whether it be how they market or produce their products, we, as bloggers, will share this with our colleagues. The opposite also holds true with wonderful finds.