I think the plan behind bip101 was that the average internet connection will likely keep getting faster with time, even today some people have 1Gbit fiber connection at home, others are probably watching 4k netflix right now.
Average internet connectivity improvements only give about 30% per year optimistically. BIP 101 was far more aggressive than that.
And while some minority of the world has 1 Gbit available, requiring it would be saying nobody else can use Bitcoin.
I'm only slightly rural and I can't get better than 5/0.5 Mbps yet.