Taste
Seems to me that this thread shows the essential futility of the original article. There is virtually no concensus on what is good or bad. Also, just because YOU don't like a show doesn't make it crap and just because I like it doesn't make it great.
You can attempt to analyse shows on the basis of some arbitrary checklist of qualities but once again you descend into a morass of argument over what should be judged good and bad. Fine for a university course on contemporary media but essentially useless otherwise.
In the end, a show is good if enough people watch it to pay for its production and encourage the makers to produce more of the same or similar. Unfortunately that makes a lot of stuff "good" which I personally loathe so I don't watch much TV nowadays.
Me, I liked (in no particular order) Luther, The Wire, Lewis, Hustle, West Wing, Fringe, Spirals, Wallander, The Borgias, Rome, Firefly and many others. Equally, I'd rather watch reruns of Porridge or Yes, Minister or Mash than most recent comedies.
You are always likely to have more good US shows than British simply because they make so many more. They also frequently can excellent shows for silly reasons or as a result of poor ratings due to schedule mishandling (yes, Fox, I'm talking about you).
Now I'm off to watch the recent Shakespeare Hollow Crown cycle. That's not something likely to emerge from the US.