Interesting. I wonder if it has more to do with weight distribution? The MG-B GT had an almost perfect 50/50 weight distribution, honestly something like 51%/49%. But the Golf GTI has listed distribution of 60%/40%, which horrendously bad, worse than most modern muscle cars.
On skid pad, the 60 mph stopping distance on a 1973 MG-B was listed at 175 - 185 feet, whereas the recent Golf GTI's have been around 100 - 110 feet. I'm not sure how that would translate to snow, but you'd better believe antilock would be working hard to achieve minimum stopping distance under any conditions, given the big brakes they put on those today have no trouble locking up.