Again...
The rule for obtaining a fact is to have evidence of something force to produce an exact model of what is evidenced.
For example the moon and a book about the moon containing facts in the form of words, pictures and mathematics. What is in the book is basically a 1 to 1 copy of the actual moon itself.
The rules for opinions are entirely different. For an opinion the rules are that the conclusion must be chosen, and the conclusion must be in reference to the agency of a decision.
The word "agency" means what it is that makes a decision turn out the way it does. If you can go left or right, and choose left, then "agency" is defined as what made the decision turn out left instead of right.
For example, the painting is beautiful or ugly. Either chosen conclusion is logically valid. The word beautiful refers to a love of the way the painting looks. The love is the agency of a decision.
Therefore the existence of love is a matter of opinion, it is believed to exist, and love chooses the way things turn out.
So you can categorize between matters of fact and matters of opinion. Opinion applies to the agency of decisions, and fact applies to the way the decisions turn out.
When you look at what atheists write it is clear they do not accept the validity of opinions, subjectivity. They only accept facts as valid.