Actually, I believe by the time of the story, the vast majority of the town was either composed of Offspring who just hadn't finished maturing yet, or were the parents of Offspring. They didn't need to ignore the problem, they were all in on it. Only people from out of town ignored the problem... well, except the protagonist.
I doubt the tuxedos ever came into fashion, considering Lovecraft described Deep Ones as smelling like rotting corpses, and looking less like Merv and Neri, and more like
this. They weren't 'fishmen', they were 'fishfrogs' with JUST enough 'man' added to be disturbing.
Which, of course, makes it very much a 'Wicker Man' scenario, because you
would not have sex with that unless you were a fanatic.
EDIT: Here's the exact passage where Deep Ones make their first real appearance:
I think their predominant colour was a greyish-green, though they had white bellies. They were mostly shiny and slippery, but the ridges of their backs were scaly. Their forms vaguely suggested the anthropoid, while their heads were the heads of fish, with prodigious bulging eyes that never closed. At the sides of their necks were palpitating gills, and their long paws were webbed. They hopped irregularly, sometimes on two legs and sometimes on four. I was somehow glad that they had no more than four limbs. Their croaking, baying voices, clearly wed tar articulate speech, held all the dark shades of expression which their staring faces lacked.
But for all of their monstrousness they were not unfamiliar to me. I knew too well what they must be - for was not the memory of the evil tiara at Newburyport still fresh? They were the blasphemous fish-frogs of the nameless design - living and horrible - and as I saw them I knew also of what that humped, tiaraed priest in the black church basement had fearsomely reminded me. Their number was past guessing. It seemed to me that there were limitless swarms of them and certainly my momentary glimpse could have shewn only the least fraction. In another instant everything was blotted out by a merciful fit of fainting; the first I had ever had.
So yeah, they aren't pretty. Now, I thought for SURE there was mention that they smelled like corpses, but I'm starting to think I remembered that wrong because I can't seem to find the passage anywhere. Still, one would assume they smell like fish, which still isn't exactly the sexiest thing in the world.