Yeah that is really arguing tendentiously against subjectivity altogether. You argue everything towards fact, which requires evidence. So then opinions must be backed up with facts, and opinion alone is not persuasive.
I like icecream, the painting is beautiful. That is opinion. There is nothing wrong with it. Same, I believe in God, is opinion. There is nothing wrong with it, or you do not understand or accept subjectivity.
Yes, there is nothing wrong with your opinion based on your experience.
Can you reverse the argument, and talk about the "deficiencies" of fact, in that they are not opinions?
The problem with facts? There are, often enough, inconvenient exceptions. People invest a lot into theories and they don't want to verify every possible exception.
Facts are often situational. You have to isolate extraneous influences which often can isolate it from reality.
In the laboratory you have to limit what can affect your experiment. In trying to isolate cause and effect. However this also takes it out of the natural environment. What happen in the laboratory is not always what happens in nature.
Generally facts work well enough, often enough to provide persuasive proof. Doesn't necessarily mean they are precise. Just accurate enough to work with.
See I can show you by following the same steps that you can duplicate the results. So you can accept the truth of that for yourself. I'm providing you the same experience I had.
With God for example. I can't provide you with my subjective experience with regard to God or beauty or love.I have to rely on you having had similar experiences. I've no facts to persuade you to accept anything I say. However if we have had common experiences, maybe we can relate to that.