If it's become common enough that Nielsen must also now report DVR views when they are reporting television ratings, then a significant chunk of the world is using DVR. It's why the networks don't treat shows with high DVR ratings the same way they treat shows with high live ratings: because DVR viewers skip commercials.
I remember when all the Stargate shows were cancelled. It was often pointed out that the DVR audience was still quite strong. So why did Syfy had to cancel? Because the DVR audience doesn't make them any money, and because the DVR audience is not in their live audience that does make them money. SG-1 went for ten seasons, but even SG-1 started losing the live audience to DVR.
And sure, you can say that a sci-fi show will have a more technologically oriented crowd, but it's telling that even the daytime soaps have been affected to the point that some of them, which have run for decades, have also been cancelled. Their audience didn't disappear. In fact, in an economy with slow job creation, their possible audience probably grew. But technology also changed, and now they could watch one soap on NBC and record the other on CBS. Well, they previously could at least, not anymore, since many soaps have been cancelled.
This is measurably untrue. In Australia, for example, the level of playback, or time-shift, viewing is a very low, but increasing, percentage of total TV. Here in Australia we measure using an audio-signature match to track every minute of the day for television watched in the Nielsen panels. In the US, it is my understanding, that they actually track the commercials watched by way of a code inserted by the broadcasters into the commercial stream. Anyone skipping over the commercials would obviously not contribute to the ratings in such a system.
Television advertising is a multi-billion dollar business. Advertisers are extremely savvy, knowledgeable and are armed with plenty of statistically relevant data that proves that their advertising money isn't wasted.
I suppose you have a good point. I've never had DVR and don't know many people who have, so this was never an option for me. With that said, I feel obligated to point out that these people wouldn't need to skip the commercials if they didn't exist in the first place.