On the topic of the main thread, though, I think @FatAnkles has nailed it: if you need a car for work, as so many do, you then compare the cost of public transport with the cost of driving, and it's often unfavourable. When you factor in the convenience of travelling by car, choosing the option that is both more expensive and much harder work seems like madness.
If you don't have a car, then you can view the cost of public transport like anything - do I want to go to this place enough to spend that or not? With no alternative, the cost of public transport isn't just 'the most expensive (and often least convenient) option'
I do also think that those who live in cities don't realise how lucky they are to be able to access decent public transport, not just around the city, but to other places as well. I lived in London for most of my life, and only learned to drive when I moved away. I hadn't really appreciated that it wasn't just commuting across the city, it was being able to get to other places really quickly and easily as well.
You can get trains and coaches to almost anywhere in the country, not to mention the continent, and you don't even need to book or plan in advance for many of them as there are so many options.
I now live near Cambridge and was planning to go to Oxford - a 1.5 - 2 hour drive that would cost £40 in petrol max. To get the coach, I would have to drive into Cambridge (25 mins and extortionate parking costs) or park and ride (probably 40 mins, costs a pound, but you have to be back by the last bus at 8.30pm), to catch a coach (£30 ish), spend more than 5 hours on said coach only to have to wait until 2.30am the next day for the next coach back, which takes 6 hours and 45 minutes.
Getting the train only takes 3.5 hours each way but costs nearly £100. I have never really appreciated how easy it was to get around until I moved somewhere where it's not an option!