I mis-read this in an interesting way: some startup ventures may seem like "not a big deal", but if they save 1% of the US population 1 minute of time every month, that's almost 70 person-years per year.
I can't imagine how much time GMail has saved for me that I would have spent setting up mail clients. Ditto for reddit, or news.YC - there is no way I could have found out and kept track of so much information out there in the blog/entrepreneur community while being a full-time student, doing research, and working two part-time jobs.
This is not to say we shouldn't donate more of our time and money to giving to those in real need, of course, just that sometimes we give to society indirectly, or even without realizing it.
I used to work at a large, very large, software company. I learned not to buy the argument of ("Hey, design this right and you'll save 1 minute on 450 million machines") as a motivating factor. You just don't notice small things enough, and there are a million small things every day. (Did you notice the new wide-mouth soda cans? They do save you time gulping. But would you be satisfied being their inventor?).
Personally, I'd prefer to have a large impact on a few people and grow from there. But that's just me.
Chase dreams. Take risks. Fail often. But love the whole process as it unfolds.
All forms of endeavor involve some form of risk management whether cognized or not. The prospects of a startup with the possiblity of high equity yield over a short period of time being a good investment increase with the competence of the original founders. Obviously PG was competent. The only reason you should 'fiercely disagree' is if you are not, in which case your argument only applies to yourself.
But tomorrow holds no promises. There's no promise you'll be alive tomorrow. No one can guarantee that. My objection is that it does take some blind passion to work more today for more relaxing time later, but there's no guarantee that you'll be alive.
And of course, not everyone is going to run a series of successful technology startups. Newsflash, I'm not Paul Graham! I'm sure that he's more competent than I am.
Get a little perspective.
Saving time is to me the most important point of doing a startup. You compress the tedious business of making a living into the smallest number of years, instead of letting it drag on through your whole life.
Startups often do dramatically novel things, because that is the way to create a lot of wealth fast. But that benefit is extra.