Cable plants are generally weak on upstream bandwidth. Around here, there's only 4x 6mhz channels allocated for upstream, meaning about 100 megabits is shared across an entire node, which is 100's of homes. Downstream, on the other hand, is 32+ channels, plus a DOCSIS 3.1 OFDM channel, providing over a gigabit of bandwidth (shared.)
DOCSIS 3.1 was supposed to also improve the upstream situation, but OFDM upstream is no where to be found yet, as supposedly they have to upgrade all the amplifiers to support more bandwidth in that direction. Most people don't care. They're not uploading tons of files.
I'm hoping to get fiber someday.