If you are thinking about it on paper, the bus running every half hour doesn't sound so bad, until you're waiting at the stop and you miss a bus or it's delayed. Then you're waiting a very, very long time. To people who never take transit, that's probably fine. Why do you care. To people who only take transit, they're expecting it, it's baked in their lives. But the important part, what really impacts our cities, is what happens to people for whom transit is an option.
The spiral goes like this. You go to take the bus instead of driving, thinking "I'm going to o have a couple drinks" or "I don't want to worry about parking where I'm going." So you take bus. First bus is right on time. But then you transfer from your neighborhood line to the line that takes you where you actually want to go. And your bus is delayed. And it only comes every 30 minutes. And then you're waiting, 40 minutes later, wondering where your bus is, knowing you could have driven there in 20 minutes.
Why would you ever chose to take a bus again? The bus made you waste precious time on your day off just sitting there. So next time you drive. Ridership goes down. When the transit authority asks for more money for more buses and more drivers, people point to the ridership numbers and say "why should we pay for this instead of paying for our schools/police/baseball stadium/parks/police again (let's be real that's who's taking all the money)?" If we want to increase ridership we need to actually design and fund functional transit networks. If we want people to actually ride the bus we need to make it a better option than driving, which means reliable service, which you don't get with a bus every 30 minutes.
Every 15 minutes, everywhere, all of the time.
