I think it's weak when it's essentially the only argument a person has against religion.
Hardly anyone treats it as the only argument against religion, but for many people here it is a fully sufficient argument. You just need to apply the principle of parsimony (Occam's razor) correctly.
Now a very weak way of applying it is as follows "In the absence of evidence of a deity, a hypothesis of no god is simpler/more parsimonious than the hypothesis that there is a god. So there is no god". If that's what you think we're arguing, I can understand why you think it weak.
However, a much stronger formulation looks like this. "If there w... (read more)
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.