It's critically acclaimed because it's original. A critic (and I know this having worked as a reviewer) has likely seen every single show that came out every year. When you've seen generic sitcom A through F, you're going to love something that's original right through from premise to characters (the characters do fill out into the 2nd season, but Fuller has a problem that his main character is often a complete vacuum - like Dead Like Me the main character was simply a way too present observer; by the end I literally loved every character but the lead).
Better Off Ted suffered the same problem (different creator) with the main character being vacuous. His boss was great, his colleagues were great, his daughter was great, I even liked the narration because it was out-of-character from the main character.
I find with the major sitcoms people relate to the main character and solely the main character. I think the main reason Chuck Lorre has done so well with Two And A Half Men and The Big Bang Theory is that it's not just the main character that you can relate to, meaning you get the unbelievably avid fans from those "critically acclaimed" shows making huge noise and driving a near doubling in viewers of their shows (the big bang theory went almost 7-million viewers from the first till third season). You don't see this growth in your average series, it tends to start large and decline continuously (Hawaii Five-0 dropped 4-million viewers in the first 4 episodes).
Better Off Ted suffered the same problem (different creator) with the main character being vacuous. His boss was great, his colleagues were great, his daughter was great, I even liked the narration because it was out-of-character from the main character.
I find with the major sitcoms people relate to the main character and solely the main character. I think the main reason Chuck Lorre has done so well with Two And A Half Men and The Big Bang Theory is that it's not just the main character that you can relate to, meaning you get the unbelievably avid fans from those "critically acclaimed" shows making huge noise and driving a near doubling in viewers of their shows (the big bang theory went almost 7-million viewers from the first till third season). You don't see this growth in your average series, it tends to start large and decline continuously (Hawaii Five-0 dropped 4-million viewers in the first 4 episodes).