When I taught writing (mostly freshman composition) long ago, I always crossed out the student's "I feel" and wrote in the margin, "I think." I wanted them to pass their ideas through a few neuronal pathways before putting them to paper. I was, of course, utterly unsuccessful, not any more than I was curing vague pronoun references or the misuse of apostrophes.
But there's something about the use of "I feel" that reveals what a sorry state our culture is in.
1. You can't disagree with feelings. If I say, "I think the issue is so and so," you can point out my errors of logic, adduce contrary reasons or evidence, and so forth. You might even prove me wrong. But if I say simply, "I feel that the issue is so and so," what can you say? (If I say, "I feel happy," you can't very well respond, "No, you don't.") So feelings are the safe, lazy, thoughtless way to present your ideas, however unreasonable or poorly supported they are. Score one point for not needing to think.
2. Feelings are based on personal experience. No need for research or even taking a poll. All you need to support your opinion is your own example. External statistics, research, evidence, reasons, arguments, and the like are simply not necessary, not applicable.
3. It makes you think it's about you. What this feelings-based philosophy amounts to is narcissism, worshiping your own (bigoted?) opinions. If you thought the conquest of objectivity by subjectivity was horrible, we're now faced with pure solipsism as king of the world. (The only question is who has the power to impose his solipsistic view of the world on everyone else?)
It seems that in the public schools the perfect storm that combined the self-esteem movement with the postmodernist view that any given text was subject to an infinite number of interpretations, resulted in celebrating the use of "I feel."
Teacher: "Why did Hamlet fail to act?"
Jane: "I feel he was too busy lusting after Ophelia."
Teacher: "Good, Jane."
Tom: "I feel it's because he was gay."
Teacher: "Good Tom."
Sally: "I feel he secretly wished he had killed his father so he could marry his mother. You know, Oedipus."
Teacher: "Good, Sally."
Bill: "I feel that he was busy researching ways to kill his uncle."
Teacher: "Good, Bill. My, I feel what a great and thoughtful class you are."