I'm both a father and a startup founder, and I fully agree with his comment and don't think it sounds bad at all. Being a parent takes a good chunk of your time and energy, at least if you want to do a good job of it. That leaves less time and energy for other things, making it more difficult to do things that require a ton of both, like start a company. As gizmo686 says above, these challenges can of course be overcome, and obviously I feel it was worth doing so. But the statements are still true, and I don't see how acknowledging them makes one a bad person.
This is a tricky area of ethics though. Ideally everyone would have equal opportunity to do anything they want to do, including start a company and/or have a family. It is generally culturally accepted that it would be unfair for one's marital or parental status to have an effect on their career prospects. And I agree that that's a noble ideal. But imagine you're an investor with two hypothetical identical investments to choose from. They are identical in every way except that you know one of the founders is single and plans to remain so at least while getting the company off the ground, and the other is a parent with six children (to use an extreme example). It seems reasonable to expect that the former would be more likely to succeed, all else being equal. As much as you would like both to have equal opportunities, is it fair to force you to ignore this piece of evidence when making your choice? (What if you're investing others' money and have a fiduciary responsibility?)
There are two conflicting ideals here as I see it, and no perfect way to reconcile them fairly.
At least with my hypothetical above, you could say that the "family founder" chose to make family a priority, so in some way it is fair that they sacrifice some potential to receive investment in their startup. Even if we accept that though, it gets trickier if you instead consider male and female founders, both planning to have families. For simple biological reasons, even aside from cultural ones, the female time will probably have less time to focus on the startup, to some extent at least, but obviously she didn't choose to be female. So again you have this conflict, where we would certainly like to treat everyone equally, especially in areas they have no control over, but at the same time it is unfair to force people to make less optimal investments all else being equal.
You could draw parallels to favoring more attractive applicants to hospitality jobs, or even more intelligent applicants to programming jobs say. You don't control your intelligence, so it's not really fair that it affects your prospects. On the other hand, it's certainly not fair to force an employer to hire a less intelligent applicant. It seems like the general rule in cases like this is that if the difference materially affects a one's ability to do the job, generally it is ok to 'discriminate' based on it. So it's ok to discriminate based on weight or skin colour for an actor, but obviously not for a programmer. The contentious areas seem to be ones where the (potential) impact on performance is less direct. The parenthood debate would seem to fall under that category. A more obvious one would be something like physical appearance of waiters and waitresses. It's not as clear cut as an actor, where it's obvious that matching the part matters, but at the same time it's fairly obvious that having attractive waitstaff could be beneficial for a restaurant.
It seems to me that the average societal reaction in these grey areas is a sort of subconscious group decision that the benefits to one side outweigh the detriments to the other. So if we say it's wrong to discriminate based on parental status, what we're really saying is that we as a society value parenthood sufficiently that it takes precedence to some extent over other rights. These kinds of tradeoffs are made all the time; for example, we value free speech sufficiently that in many cases we allow it to override people's right not to be subjected to material they find objectionable. We value a basic standard of living such that we 'forcibly' deprive wealthier members of society of their property (via taxes) in order to redistribute a portion of it to the less fortunate. (In fact, we force people to contribute to many things that they may not personally support via taxes.)
Anyway, this ended up being far more than I had planned to write, but I guess my basic point is that few things are black and white. Usually some sort of compromise is necessary, and the goal is to find the one that best matches our societal values. Often our instinctive reactions to these grey areas are representative of a personal or societal value that we haven't fully consciously expressed.