I used to say that. Now I live in a rural area, and the fastest speed that's even available is 5Mbps (and the uptime isn't great). My house also has zero cell service from any provider.
It's also a bit presumptive that everyone can afford a 100Mbps connection. The last place I lived, it was like $120/month for 100Mbps. Not everybody can afford that.
That being said, has anyone out there come up with creative solutions for working remotely on a crappy connection?