Retreating into irrelevant and questionable technicalities that distract from a debate topic is not helpful. The parsing of those terms in context in not relevant. Too often terms used in a forum's informal setting are debated as though they were used in a research paper. It's usually easy to work out the points others are trying to convey, regardless of use of language. The points made by ESL members may not be correct English but they still manage to make their views clear.
Having said that, I agree with you that unsubstantiated claims* are not necessarily a positive contribution to a discussion. In my observation, claims* made without solid reasoning tend to act as noise in a forum.
Since negativity tends to attract far more attention than positiveness or neutrality (hence the mainstream media's conveyor belt of misery and horror) a dodgy claim* can easily derail a thread and distract from productive discussion.
* claim/opinion/notion/assertion/declaration/argument