Indeed, it's rather hard to give an objective definition of what constitutes a 'revolutionary' advance. I'd take issue with this as well:

It would be crazy to claim that a mobile phone is further from a regular phone than a regular phone is from no phone at all, ditto for Internet versus TV.

But it's not like there's some obvious objective metric of 'distance' between technologies in this context. As one example of how you could argue mobile phones are more revolutionary than land lines, in much of the developing world the infrastructure for widespread usage of land lines was never built due to problems with governments and social structure but many developing countries are seeing extremely rapid adoption of mobile phones which have simpler infrastructure requirements. In these countries mobile phones are proving more revolutionary than land lines ever were.

I'd also very much dispute the claim that the advance from no TV to TV is more revolutionary than the advance from TV to the Internet. I don't think it makes much sense to even make the comparison.