The link you provided cites advertised plans boasting hypothetical peak bandwidth possibilities and not real life bandwidth averages.

Additionally, this doesn't address all the concerns:

1) Latency caused by larger blocks incentivizes the centralization of mining pools
2) Not everyone worldwide lives in locations which has bandwidth growing at the same rates
3) Advertised bandwidth rates are not the same as real world bandwidth rates
4) ISPs often put soft caps on total bandwidth used on accounts and stunting the user speed to a crawl.  More are no longer advertising unlimited bandwidth per month and setting clear total amount transferable limits and hardcaps with overage charges.
5) Full nodes at home need to compete with the bandwidth needs of HD video streaming used by most users which is getting increasingly demanding. Most people don't want to expend most of their bandwidth on supporting a full node and stop streaming Netflix and or torrenting.
6) Supporting nodes over TOR is a concern

Lets look at the historical account of real world bandwidth averages -

http://explorer.netindex.com/maps?country=United%20States

1/2008      5.86 Mbps
12/2008    7.05 Mbps
12/2009    9.42  Mbps
12/2010    10.03  Mbps
12/2011    12.36   Mbps
12/2012    15.4   Mbps
12/2013    20.62   Mbps
12/2014    31.94  Mbps

Thus you can see that even if I were to ignore many parts of the world where internet isn't scaling as fast and focus on the "first world", bandwidth speeds aren't scaling up as quickly as you suggest.