Why is it still so popular? If anybody had an answer to that, there would be a lot more shows like "NCIS" on the air. Instead of the one very successful spinoff, "NCIS: Los Angeles." And a second spinoff currently in development.
It has a lot to do with the chemistry among cast members. And that could account for the rather loopy response from a particularly devoted group of fans who spouted conspiracy theories all over the place when Cote de Pablo (Ziva) left the show this fall.
Whatever the reason for its success, it's the ultimate arrogance to dismiss "NCIS" simply because you are not a fan.
"Marvel's Agents of S.H.I.E.L.D." has all sorts of buzz, but it draws fewer of those younger viewers than "NCIS." The last three Tuesdays, "NCIS" pulled a 3.0, 3.0 and 2.9 rating in the 18-49 demo to "S.H.I.E.L.D.'s" 2.7, 2.7 and 2.5.
That's far closer than the race among total viewers. "NCIS" (18.99 million) was seen by more than 2 ½ times as many viewers as "S.H.I.E.L.D."
This is not criticism of either show. This is criticism of uninformed snarkiness from people who say, "I don't know anyone who watches 'NCIS.' "
If that's really true, you must not get out much.
It's the same sort of snark I hear from people who say, "Why is 'Survivor' still on the air? I haven't watched it in years!"
That may well be. But, believe it or not, TV doesn't revolve around you. Or me. It's all about collective numbers.
And "Survivor" still draws about 10 million viewers a week. More important, it consistently wins its time period in the 18-49 demo against regular competition. (Not up against the World Series, but that was just two Wednesdays.)
Last season, "NCIS" was the most-watched scripted show on TV, averaging 21.3 million viewers. Only NBC's "Sunday Night Football" averaged more viewers — and only 99,000 more.
A lot of those viewers are outside the demo. But "NCIS" was No. 14 on the 18-49 list, better than 196 other shows.
So snark all you want, the show remains a hit.
Scott D. Pierce covers television for The Salt Lake Tribune. Email him at firstname.lastname@example.org; follow him on Twitter @ScottDPierce.