Although answers on a site like IPS will be opinion-based to some extent, I recently came across certain questions that are not themselves primarily opinion-based, but seem to have attracted a few answers that are, in terms of making assumptions about the motives of the protagonists, which are not warranted by the information provided by OP, and basing the answer on those assumptions. I should not like to point to specific examples if it can be avoided, because in such cases the meta discussion often tends to focus on those particular examples. Typical form of an opinion based answer is as follows:
from your question it seems to me that the underlying intention of Alice and Bob in asking Eve to drive Mallory to the supermarket was to...... from which it can be concluded that......
I think it was very ............ of Mike and James to do ..........., which clearly shows that they want to ........... So you need to .......... which would be a good solution to your situation
when in fact there is no information in the Q for anybody to authoritatively make that assumption.
It is a common error made in good faith, and I might even have written some such answers myself, but it was not pointed out by anyone at the time. Are we OK with such speculative answers, or what do we do with them?
Note: these answers are not really "off-topic" in the manner described in this meta question Can answers be off topic? - How to deal with answers that address legal issues but rather they are highly opinionated in being based on unfounded assumptions.