For once, I agree with the critics. The Last Man on Earth was terrific for its first couple of episodes and then quickly went off a cliff.

Just when it became too much for Will Forte to do on his own, they brought in one of my favorite people in entertainment, Kristen Schaal. Their characters’ different approaches to civilization’s collapse brought some great comic moments.

The first half-hour asked and answered the question “How would you make the most of things if everyone else was gone?” Then with Schaal on board, it asked how you would make the most of things if the one other person drove you crazy.

Then … let’s let Salon’s Anna Silman sum it up:

It’s disappointing to see how fast the show has veered away from its adventurous beginnings into predictable sitcom plot-lines and stereotypes. When the cast was still only Phil and Carol, their odd-couple banter felt fresh, and I looked forward to following them on their bizarro Adam and Eve-like quest for repopulation. But with the arrival of January Jones’ Melissa in episode three, and the formation of a plot based purely on the old-school love triangle, much of the show’s early promise seems to have been jettisoned in favor of a far less exciting approach.

AV Club’s Caroline Framke had similar disappointment. She liked the possibility of January Jones being the rational one between Forte and Schaal’s extremes, but the whole “I’d rather be having sex with the other one” plot is as hackneyed and tedious as it gets.

Huffington Post’s Maureen Ryan didn’t even like Schaal’s introduction because her character was such a female stereotype. It’s a valid complaint, but I thought Schaal did such a nice job taking her character beyond stereotypes into lunacy — as she does in her standup comedy and her voice work on Gravity Falls and Bob’s Burgers — that she overcame most of the underlying sexism. She even brought a bit of dignity to the role, demanding and getting respect.

Here’s another way Last Man on Earth could have played out …

Forte and Schaal struggle for another 4-5 episodes, gradually making progress restoring basic comforts (plumbing, for one) and getting along with each other, even falling in love. They even restore power, get on the Internet and find … New Zealand survived the virus. They make contact and prepare to pack for New Zealand, only to find that a bunch of New Zealanders want to come over and live in Tucson. Forte and Schaal look out over their newly populated town with satisfaction.

End of series.

All told, maybe it’s 12 episodes. And that’s OK.

Continuing indefinitely is generally an American thing. Many of the classic British shows — Fawlty Towers, The Office, The Young Ones — only produced 12 episodes. In those cases, it’s regrettable. Surely The Young Ones could’ve gone on a bit longer. I was still holding out hope for a revival, akin to the periodic Absolutely Fabulous six-episode spurts, until Rik Mayall died. The Old Ones would’ve been terrific.

Not here. Shows continue until the ratings slide or everyone in the cast finally decides to move on after devoting most of their careers to a single role.

That brings me to The Blacklist.

It’s a terrific show. I could watch James Spader’s inspired Raymond Reddington character all day. But it’s wearing thin.

How many times can we have characters reach the brink of learning the mysteries surrounding them, only to back away? How long can Liz continue to deal with Red’s refusal to pull back the curtain and explain, at least partially, what this is all about?

The Blacklist should either run for about 50 episodes total or come up with some sort of extra level of mystery to make it worthwhile. The former might be more palatable.

So it’s a puzzler. Why must open-ended Britcoms leave us so soon while American shows drag out limited premises for so long? Why did Lost continue for so many seasons, only to conclude with, “Uh, yeah, it’s some sort of purgatory”?