Yes, I agree. These lists run the risk of leaving out potentially great themes, although I believe they did a pretty good job of representing many of the best ones. (But no "I Love Lucy," perhaps one of the most iconic of themes if not of shows? For shame, I say!) 

Vic Mizzy was a legend, with his Addams Family and Green Acres themes. He's also responsible for one of the most remarkable opening tunes of a show absolutely no one remembers but me. It was called The Pruitts of Southampton and starred Phyllis Diller, around 1966 or so. The theme song (which you can hear here thanks to YouTube), summed up the premise of a wealthy family that went broke but tried to pretend they were still rich. It was sung by the cast and even though the show didn't last long, it's still one of my all time favourite intros.  

Mike Post once told me in an interview I did with him a few decades ago that he wrote the theme for Hill St. Blues in about 10 minutes. They told him what they wanted, he thought about it, sat down at the piano and out it came. He's since done so many TV theme songs, I've lost count.

Although I doubt he has as much work as he once did. The era of the TV theme is fading, if not completely done. There are still a few shows that use them (This Is Us, Law & Order S.V.U. and The Conners are three that come to mind) but many now put the opening credits over a scene instead of over an intro and get right into the show to discourage tune-out. 

It's probably a much better idea, but I do miss those classic 30 second songs that defined a generation of TV programs and are often more memorable than the shows themselves.