Just a question - why build public transport at all if it's undesirable? That just pushes everyone who can afford NOT to take it out, which leads to pollution, but worse, the effect that the populace using the public transportation are probably seen by others as 'more undesirable', leading to a snowball effect of people not using it until it's fully subsidized and terrible. That's what basically happened to busses in my old city. Even the less well off people would tell you not to ride one because it's full of crazies/homeless/beggars/etc. We're like, worse off than if they'd never have built it at all.

If we're serious about modernizing and reducing our carbon footprint, we should provide reliable, safe, comfortable transportation that people want to take. Not relegate it as a public service for the needy. (though the both can work together)

If you take a look at surveys on the subject, nobody likes buses, and everyone loves the idea of trains, though they have more mixed feelings on the implementations. Buses are generally viewed as transportation for the poor and the young; I don't see how we can change that.

I think the 'solution' is to replace buses with smaller and more efficient urban mobility solutions; buses are not that efficient (as they spend most of their time driving around almost empty), so this is the lowest-hanging fruit anyway. If I knew how to create these solutions, I would be working on them right now, but I think some combination(s) of car-sharing, high efficiency vehicles, self-driving technologies, and electric bicycles will eventually replace buses.

I don't like buses, and I vastly prefer trains over them.

However, I've taken some really, really bad buses (SF), some middle-of-the-road buses (Seattle), and some rather good buses (Vancouver).

If you want to improve bus efficiency, the lowest-hanging fruit is switching the less-used lines to 24-person shuttle-buses. Vancouver uses that model heavily.

The next lowest-hanging fruit would be actually getting people to use the bus. If the reason they don't use the bus is 'it doesn't take me where I need to go', you can fix that. If the reason they don't use the bus is 'only crazies and poor people take the bus', you can fix that too. Transit systems that are used by everyone, as opposed to just 'undesirables' tend to run a lot better.

Also, keep in mind that most cars on the road are $20-50,000 vehicles that drive 75% empty, and spend 95% of their lives sitting in parking lots. That's a damn low bar for 'efficiency' that even a mostly-empty bus can match. Likewise, taxis are vehicles that spend ~30% of their time driving empty, and only transporting 1 person the vast majority of the remaining time. (While costing ~$30/hour to operate.)

You're right about buses, but I don't think that's inherent to buses, just how we've implemented them. In other countries, buses are comfortable and air conditioned and basically anyone and everyone rides them. If we could figure out how to make them safe, clean, and comfortable, then of course they wouldn't be empty most of the time, and would run at capacity(which would be a good problem to have).

Rail I think is obviously preferred long term, but setting up a fleet of electric buses could be done in a matter of months, vs a simple limited rail that takes many years.

Buses almost always run at less than 50% capacity, as people are going to or from school or work, but not both (i.e. morning rush is in the opposite direction of evening rush). The other unsolvable problems for buses is that they necessarily increase commute distance and time, as people must take a more indirect route to use buses (as opposed to individual transportation), and they are not flexible (i.e. they have limited peak capacity and fixed schedules).