30 minutes just isn't really long enough. Losing a game when you're ahead simply because you're thinking about moves and then have to rush due to 30 minute timed games just isn't right.

If you select custom you can set a time longer than 30 minutes.

I'm pretty sure you can go longer than 30 min. Just set custom time controls.

Yes you can go custom,  but a lot of people just choose one of the timed options and click match. Would be a lot harder to get matches as opposed to if they just added a 45 minute or even an hour option.