See my post upthread about the need to define what criteria we’re using to define “underrated.”
As for OP, I think it made a bigger dent in the public consciousness than arguably any EON Bond of the 80’s. Partly this was due to the “naughty” title, partly to all the free publicity from the press-fueled “Battle of the Bonds.”
In my neck of the woods, the conversation usually went like this among non-devotees:
“Have you heard? Sean Connery is doing a new Bond movie!”
" Wow, that’s wild! I always liked him better than Roger Moore. "
“Well, this year they’ll be in direct competition, because Moore’s new one is coming out, too.”
“Wait, they’re still making those?”
Meanwhile as a Roger fan, I’m in the corner fuming.
I still remember standing in line at a theater in Lynchburg Va when four Japanese tourists asked for tickets to Octopussy and giggled like they had just gotten away with something by saying the name.