Really? Quick thought experiment for you: given a range between Crr of 0 and Crr of 1, is rolling resistance irrelevant? I should hope you can see that the answer is no, because there's a point long before Crr=1 where the bike is immovable by any human being, and a point long before that where the effort to move the bike is unreasonably high. Obviously, the range between a fast road tire and a slow commuting tire is a lot smaller than 0 to 1, but at what point does Crr become unimportant? This is basically a grain-of-sand question - if accumulation of something is important, how can you say that one atom of that thing doesn't matter?

I'm not just trying to be a smart-ass here. Rolling resistance is not a trivial component of the drag on a bicycle. At moderately high speeds it can be as much as one fifth to one fourth of the total resistance to movement. At slow speeds, it will be a lot more. Most importantly, from the perspective of a commuter, the effect of rolling resistance is constant at all speeds, including very low speeds. For this reason, rolling resistance is arguably a lot MORE relevant to a slow-moving commuter than to a bicycle racer. And as a bike racer myself, the endless invocation of "unless you're racing" gets pretty old. Because of the way bicycle racing works, with drafting and tactics, tire Crr would predict the time of your commute a lot better than it would the outcome of a road race.

The actual reason that most commuters need not concern themselves with rolling resistance is that most commuters are traveling short distances. If you're riding 2 miles each way to get to work and back home, like I do, the difference in total effort and time between a fast tire and a slow tire are miniscule. But as distance expands, so does the cost of higher rolling resistance. I don't blame anyone for thinking about how fast the tires on their commuting bike are. We do want our commutes to take less effort, don't we? We wouldn't turn down the opportunity to get home five minutes earlier for free, would we? Of course there are trade-offs to consider, like tire life, price, cut resistance and so on, but that's really nothing new.

Maybe this seems like splitting hairs, but the insistence that performance doesn't matter for commuting gets under my skin because it's so trivially falsified. OF COURSE you care about speed and rolling resistance! If a bicycle weren't faster and easier than walking, you wouldn't bother with it, would you? How anyone stacks up their priorities is up to them of course, but it's ridiculous to say that performance isn't on the list.