Maybe some people want higher quality articles?

There are good free publications out there, but a lot of it is just regurgitating press releases or are little more than editorials. The reason is simple enough: people who write for a living need to be paid. Free publications depend upon advertising revenues, so the editorial staff tends to cut corners and the authors tend to go for quantity over quality.

Magazines have other things going for them too, some of which the "subcompact publishing" addresses and some of which it doesn't. This includes everything from being self-contained (i.e. you aren't reading from a fire hose) to affording a more visual layout.