Marco Arment has a dour post about the Mac App Store this morning:

The Mac App Store is in significant danger of becoming an irrelevant, low-traffic flea market where buyers rarely venture for serious purchases. And I bet that’s not what Apple had in mind at all.

It would be easy to dismiss this as the grumblings of an old-guard nerd who refuses to get with these times of casual apps and computing for grandmas, if you were so inclined. Has he learned nothing from the success of iOS?

But here’s something to consider: however iOS-y the Mac becomes, it is not iOS. It is already not the first choice for casual users. The Mac is not a platform of portable, extremely affordable lifestyle-devices. And it’s not going to get there, either; if anything, iOS will become more compatible with the needs of professional computer users.

As casual users choose iPads and iPhones over computers, the percentage of Mac users who are high-tech professionals is only going to increase. I would not hesitate to recommend an iPad over a PC or a Mac to my parents and friends with casual-device needs at this point. We early adopters of iOS have been waiting for this, and we’ve slowly begun to brag about about it lately, right?

But I can’t recommend an iPad over a Mac to my older brother, who designs books for a living. Or to my younger brother, who develops games. Or to the mirror. And that’s totally fine, of course. If iOS gets to the point where we can use it to build all the things we build today, bully for iOS. But in the meantime, we’ll continue to have Macs. Sooner or later, we’ll make up most of the people who have Macs.

And the Mac App Store, in its current incarnation, just isn’t built for us. It’s built for people looking for casual apps and games. (Sorry, there’s one more category: Apple’s own apps, which don’t have to play by Apple’s rules.) And that’s also fine. But put the two facts together—the loss of casual users to iOS, and the loss of non-casual apps on the App Store—and it starts to look like a problem.

It’s good for us Mac users that we don’t have to limit ourselves to apps from the Mac App Store; good old direct downloads still work fine. But it’s not good for the Mac App Store that we will probably increasingly take advantage of that option in the future.