We know first person is narrated with I, my, us, we, etc. And third person with she, he, they, and them. So all that’s left is second person which uses you.
There are two distinct aspects of second person.
1) singular — “you” means one person
2) plural — “you” means multiple people
The only way to tell if a “you” statement is plural or singular is to examine the context of the sentence. In this case, “you blame” does not provide us with enough context to be singular only.
If it had instead been: “you all blame” we could have deemed it ONLY plural second person; but in this case, it could be either or.
