Agreed, compact spares are completely stupid.
Respectfully, I'm not sure I agree with you.
There is a significant difference in weight between a full size spare and a compact spare. There's also a difference in diameter, which means that a larger (and thus heavier) structure is required to house a full size spare.
In the past 45 years of driving, I've only ever had one flat tire. But, I've driven many hundreds of thousands of miles.
I'd rather take the fuel savings (and performance improvement) that comes from having the lighter compact spare than the questionable benefit that comes from carrying around a full size spare.
In Europe, many cars don't come with a spare tire at all - instead, they come with an air pump and a can of goo to temporarily plug holes. I think that a compact spare is a good compromise between a full size spare and the air pump / goo.
Michael