Grace Slick did not like that one herself. In her autobiography, she says that she sang a lot of songs she did not like after her sober return to Starship because she felt like she owed it to her bandmates to be a good trooper after her previous years of bad conduct.
I was a big fan of Jefferson Airplane, and listened to Jefferson Starship although they were getting quite pretentious. I recall thinking the We Built This City was horrible schlock at the time. But then the 80s were a decade of unmitigated schlock. 
This article says it was first dubbed “Worst of All Time” by Blender magazine in 2004. However, the album it was one received criticism at the time, for example:
Also:
Grace Slick claimed she liked it at the time, but later recanted:
S&G wrote the song, but the hit was by Harper’s Bizarre.
I remember asking my ex-wife, about a decade ago, ‘remember that crazy music video where the kid found out his father was some sort of alien rebel and he recieved a final message from his dad via some glowing hologram?’ She didn’t believe me until I found the video on YouTube.
My addition to the list of awful number ones is “Lets Hear it For The Boy”, by Denise Williams. I hate it so much I’ve written my own verse:
My baby, he don’t wipe clean.
He got skid marks in his drawers.
But you know he’s very handy.
He helps me out with house-hold chores.
And, maybe he got bad breath.
Ya know, he don’t brush or floss.
But his cock is 10 full inches
And that is what makes him my boss.
Written by a man, of course.
Nitpick: her name is spelled Deniece.
Challenge accepted. And completed. And repeated. Many times, for decades, because I love it.
Its inclusion here is a genuine shock.
This. This AF. It’s like the word “moist” being that word that people hate, on lists of worst words, so now people who would never even have had a word they hate will list it as “OMG worst thing ever I just can’t…” because everyone knows that’s the word to hate.
Nothing draws a crowd like a crowd…
Hating fruitcake is a thing?
986,000 results
Yeah, and they totally schlocked it up. (Has there ever been a dorkier looking group?) I like S&G’s version, even if its a little twee, but that one would send a sugarplum fairly into a diabetic coma.
Oh!
No, I was thinking of rich, moist, English fruitcake. People may hate that too, but to do so is not A Thing.
I hate Yorkshire Pudding gets 1.5 million results.
I still love Red Rubber Ball! It’s a great little pop song. Being in elementary school at the time it came out probably helped. The lyrics seemed perfectly mixed-metaphorically logical: bouncing back from a rollercoaster ride of a rocky relationship like a red rubber ball sun of a new day because there’s more than one starfish in the sea. What’s not to love?
Per Wikipedia,
Even if it wasn’t a #1 Billboard hit, I think that #2 Billboard plus #1 Cashbox makes inclusion permissible. I can’t believe that it came in just behind the delightful “Grazing…”, though; I’d have guessed there were at least a thousand songs between the two.
Even when I was too young to realize that the song is essentially a male’s ultimatum to a woman to give it up or break up, the name or phrase “Lady Willpower” grated upon me. I say “name or phrase”, because it doesn’t even scan as a name-- I parsed it as “Lady, willpower” except that that doesn’t scan either.
If it were “Lady Hesitation” it would still be atrocious, but “Lady Willpower” is nonsensical.
Incidentally, although nothing comes to mind I’m sure that there’s an Internet “rule” or axiom to the effect that whenever commenters are asked to provide “worst” or “best” choices, someone will promptly show up to vehemently assert the opposite opinion.
Whereas on this side of the pond, admitting you like fruitcake (and for some, pineapple on pizza) is like saying you eat your own boogers; it engenders a mixture of horror, disgust and pity.
I’m going to file them away with the 63 million who voted for Trump.
Yeah, “Red Rubber Ball” is another perfectly fine song I’m shocked to see here.
Pineapple on pizza is one of those divisive things over here (although I’m sure many of those who claim to despise it do so more because that’s a thing than because they genuinely find it that objectionable). Fruitcake though…no, it’s not in the same league at all. Generally the fruit in question is raisins, sultanas, currants and possibly glacé cherries, and the ratio of fruit to cake is very, very high. The idea of it going stale was a huge surprise to me - it’s essentially impossible with a decent fruitcake. I make mine in October, usually, so it’s had a chance to mature by Christmas. I’ve occasionally left it as late as November, but I get a bit twitchy if that happens.
Tealoaf fruitcakes (not to be confused with teacakes, which are essentially sweetish white bread studded with currants) are a good non-special-occasion version: the fruit is soaked in tea first and often then boiled up with butter, sugar and spices before mixing with flour to create the batter - again, a moist, very fruit-laden affair.
I should probably start talking about music again though, eh?
Paul Simon refers to it as his biggest embarrassment as a composer.
Unless I missed it on scroll, I can’t believe 4 pages and no one mentioned something as pukeworthy as Foreigner’s “I Want to Know What Love Is”