Earlier quoted context omitted.
While I agree with others here that dial-up-friendly sites don't "collide" with complex web-apps (thus rendering this argument somewhat void), I sadly think the underlying problem is much more mundane: Why are word processors not orders of magnitudes faster than two decades ago? Same reason. No one wants to pay the additional costs of achieving that. Practically speaking, this means that either Random Local Newspaper…
> Why are word processors not orders of magnitudes faster than two decades ago? Because even in the 1990s, word processors weren't orders of magnitude slower than the person sitting at the keyboard, which is the ultimate limiting factor on word processing speed.
The same goes for almost any website: People with 56k don't consume much digital goods and returns from ads are most likely almost non-existent (especially if the ads are huge themselves). That easily explains a huge part of the web.
Thus, either the connectivity around the globe has to be improved (thats the route Facebook seems to choose, albeit with debatable conditions for their new "customers") or create other incentives for anyone hosting something on the web to attract people with low bandwith connections.