it was one of the lowest ratio votes to seats for decades.
As you say, a high vote reflects voter wishes, but the FPTP voting system isn't designed to match "proportion of total votes" to "proportion of seats."
The vagaries of the FPTP election system affects number of seats, but does not change voter wishes or support for politicians and parties.
Being able to talk pointlessly about ratios gives you some pleasure, I see. More than you can find in the swing among voter numbers.