Let's start with the less contentious of the unsound premises: premise 1

People are fans of bad things all the time. Take, for instance, Wiseau's "The Room". It is, by all accounts, a bad movie. Poor writing, poor acting, &c. However, there is a not-insignificant number of people who'd consider themself a fan of the movie, in spite of this. *Just because something is bad, doesn't mean you can't like it.*

The more contentious is premise 2. Without a proper background in philosophy of art (something I don't have), we can't really deeply analyze this premise, but we can say this: for most people, this is a matter of personal taste. For instance, I personally disagree with this. I think that, for instance, Forces, Unleashed, and Colors are all good games. You may disagree. But to treat premise 2 as an objective truth? It's absolutely ridiculous.

To finish, a reminder of the distinction between validity and soundness:
A valid argument is one where the conclusion *must* follow from the premises. For instance, this argument we looked at is valid as it's a simple "If A, then B. A, therefore B" argument.

A *sound* argument is a valid argument *where all the premises are true*. This argument, then, is unsound as premise 1 is *definitely* false, and premise 2 may or may not be true.

@auravulpes I am a fan of uwe Boll's movies because they're so bad.

Postal 2 though, I think it's legit funny.

In all seriousness though, for a lot of things, quality is subjective.