I don't think any discussion of Bitcoin development should be based on assumptions that it's important to listen to those with 56.6kbps modems. Bitcoin should not be designed around the lowest common denominator of technology, just to dictate that "everyone can run it."
It should be usable by most people, but there's no reason to get hung up about fringe use cases like 56.6 modems.
hazek isn't arguing about 56.6 modems.
I think it's about balance. The thing is Bitcoin is billed as a currency that users can own, on their own. They don't have to trust anybody. The minute you start decreasing their ability to have a say (and check) of what goes on with the currency you've moved away from it being a currency they own on their own. That doesn't mean higher end users can't use it, but it pushes some people out.
To qualify as "grassroots" access I think you have to look at the typical technical capability of, say, average U.S. consumers. The world follows the U.S. as a benchmark on things (for example, see the
Big Mac index). So, you want to grab technical specs from there I think, if it's a goal at all.