There are a lot of reasons to watch a show you consistently find problems with.
It's possible that you have a well-developed sense of the absurd and you find either it's so bad it's funny (Batman, for example), or it's so over-the-top that making any kind of sense is just out the window and you enjoy it for what it is (Batman works here, too).
But - to address the specific question you so artfully dodge around
- if you're held up as an expert on a particular subject (say, science fiction) and you need to speak intelligently on that subject, you need to keep up with what's being produced. You need to speak to what you find right and wrong with the new work being produced by whatever source, as with any real-world issue of society (politics, Iraq, gun control). And, you need to have adequate information to do so. Just like in any real-world issue.
So, pursuing this example, if you care about the state of sci-fi as entertainment you must watch it, and then speak out on what you like and dislike, what you expect to see in your sci-fi entertainment. If you don't, you never will see what you want to see. For most of the viewing public, that's done with the TV remote and their theater dollars. For some of us, though, that includes various internet discussion boards, which always narrow the focus so minutely that it sometimes appears we're all hopeless, mean-spirited fanboys.
I am
Dawg