If one person disagreed with it then, by definition, it is not universally accepted.
But that aside, my argument stands whether the position is universally accepted or not: all it takes is for the person you're discussing with to also agree and you have no discussion. But if that person does not agree - for one reason or another, whether it be a nuance or at a gross level - then you have discussion.
But you seem to be only considering those cases where people agree.
If the position you're holding is dependent upon what is meant by "extreme" then I would suggest it does need to be clarified. It could be that those asking for the clarification are merely posturing, but that would be for you to judge.
It can work and does work, but it needs focus on the issue being addressed so as not to be sidetracked by other considerations.
It is rarely futile, I find. Science doesn't help me discover who I am as a person. It helps me discover things about the material world around us, sure. But to understand myself? Philosophy does that for me. Science can tell me which synapses are firing, and what area of the brain may be working when I do things, but it is philosophy that helps me know who I am, know how I think, helps me refine my assumptions/beliefs etc.
Much like football.
But philosophy does lead to discovery: not discovery that is repeatable for everyone in the way that science does, but it can help us discover things about ourselves and others, why we think what we do, why others don't. And I don't mean simply learn that others don't agree, but what the root cause of that disagreement is. What they discover about themselves might not be applicable to another. For example I know I am a materialist, but I know others are not, but I can try to understand their viewpoints (while not agreeing with them) to help me better communicate with them. I have a brother who is religious. We shared the same education, he's (otherwise) intelligent, but we are fundamentally different in the way we think about things... we have fairly significant philosophical differences. I for one like investigating those differences.
Yet here you are, finding something out about the way people operate, what possibly drives people, what might drive their disagreement with you (or at least inability to initially agree) etc. And all that without discovering any "deeper truth or addressing any deeper issue".
It is true, though, that any discussion can be rendered impotent without rigour - but you might need to consider the difference between what is discourse on philosophy and what is debating tactics of sidetracking, obfuscating, equivocating and all the other things people do to obscure inability to give a straight answer.
One thing I heard about the difference between science and philosophy, though (paraphrased):
- Science is the understanding of reality; Philosophy is the understanding of why we otherwise disagree.
And to some it is as valuable to know why we disagree on subjective matters as it is agree on reality.
Or something like that.