Interpersonal.SE evolved into its current shape only recently but members made it clear early on that a question should focus on a specific interpersonal problem and contain enough details to generate practically helpful answers.
[It was meant to define the focus and scope of this website. Otherwise interpersonal skills is such a large and inclusive subject that literally any question about human interactions can fall within its domain! However the format for a question to be on-topic, not opinion based and not too broad means that the possible range of permitted questions gets restricted in the process.]
Looked at that way, this question does focus on an interpersonal problem but the problem is currently more general (OP struggles to defend his opinions in discussions with different people) than specific (as it would be if OP had an intellectual clash with a particular person.) Moreover there are too few details for a member to venture upon a constructive answer. So in the case of this particular question not only the more-general-than-specific nature of the question itself but also its being so short and lacking details might well have contributed to its closure as 'too broad'.
In a recently closed and reopened question that is essentially too broad by current site definitions, a helpful user asked that OP to include adequate details of at least one specific real-life example, which made the question much better aligned with site expectations and also much more answerable from a practical perspective:
How to support a friend with an 'insignificant' problem?
I think that's the way to go for OP to get this question reopened.