All it takes is just a handfull of guests streaming video (and I'm talking Netflix or Hulu type video) simultaneously to saturate most hotel's Internet bandwidth. After that, _everyone_ suffers poor response.
Like the article mentioned, the Internet experience is very important to me and I mention it in all of my tripadvisor reviews. Fewer than 25% of the properties I've stayed offer what I consider to be good bandwidth. By good bandwidth I mean good response for e-mail or websites like FlyerTalk at 8-10 PM. I don't generally stream video except for the occasional YouTube link.