Bubble-gum means overly sweet, simplified, happy-a$$ music aimed at pre-teen bubble gum chewing little kids doesn't it. The musical analogue of the bright side of a 50s sit com.
The Osmonds, Jackson 5, Monkees, Backstreet Boys etc.
Not the Ramones.
Punk means the opposite of bubblegum, all harmonies aside, It was primarily noted for it's anti-establishment, anti-progressive bent. Punk is maybe intentionally simple and blunt to the point of being even pretentiously unpretentious.
I guess "The Great Rock and Roll Swindle" and how that all turned out, shows that punk rock was just another case of the establishment taking advantage of young musicians and fans from its very inception under the guise of being radical and anti-establishment. Though rock-and-roll has always suffered from that indignity.
It seems like any radical music scene gets devoured by the masses and industry if it's in the least bit popular., It is eventually digested. That's why Black-Flag sounds like pop-music to me now, I think.
In today's genre overladen environment where you can have "Christian Metal Core" maybe "Bubble-Gum Punk" is a thing, but let's not throw the Ramones in there simply because they have pop sensibilities, as most punk with its anti-progressive core seems to have. I don't think it's the Ramones that are or have ever been bubble-gum. I think it's us that don't hear the radicalness of it anymore. If "Bubble-Gum Punk" is a thing let's not forget the irony of it, and let's not forget that Punk is just, along with most rock music, probably always has been tacking hard to pop, at least as long as there is money to be made.
I did read a interview with one of the Ramones years ago and the Ramone, I have no idea which one, said something to the effect of
"We thought we were just like the bay city rollers, we didn't realize that writing songs about sniffing glue and..., was something unusual"
I personally thought they were a lot smarter than that and he was just messing around.