Gee..., why didn't anyone else think of that? Cisco, are you listening? You need to make a GSR that does BGP updates faster, ok? While you're at it, you need to write bug-free software and build routers that never fail, ok?
C'mon. I'm obviously not suggesting it is as easy as "ask and ye shall receive". My point here is that demand drives the market, and if it becomes clear that routers with faster BGP implementations are what is needed, that is just what the vendors will (eventually, at least) develope. Do you think vendors have been madly increasing the throughput of their switches and routers over the last couple years just for the fun of it? I doubt it. It's because increased bandwidth is *what's in demand*. If there's a theoretical limit that prevents routers from processing BGP updates faster than they do today, I'd love to hear an explanation -- then again, I also heard convincing arguments that modems could never get faster than 9600 baud.
As for the "imposing limitations on end-users which make the (I)internet less useful", well, personally, I'd trade "less useful" for "available" is a second. Though you should understand that those limitations aren't imposed because folks have nothing better to do, they're imposed because people with experience attempt to design things that are reliable, scale well, and are manageable. Having worked for several large service providers, I assure you, hacks and one-offs don't scale well.
I'm not suggesting that the limitations are being imposed for no good reason -- I'm simply saying that imposing that kind of limitation *is not a long-term solution*, if what users of the network actually need is something else. Also, keep in mind that in the case we are talking about, the *exact reason* that users need portable /24s is for reliability -- so at least for those users, I'm sure they would rather each provider be 10% less reliable, if it meant they could multihome to multiple providers.