All very interesting. In the US it's clearly understood that a filed alternate is ONLY for planning purposes - primarily fuel. Once you get up there you can do whatever is most convenient. ATC doesn't even know what you filed.
Of course it depends what you fly too. I rarely have less than 2 hours reserve, which means that in California I can always fly to the desert if I had to. If carrying fuel costs you serious money (as in a 747) then of course you can't be as casual about things.
If I'm going to a non-ILS airport, I always file the nearest ILS (assuming the weather is up to diversion mins). If my destination has an ILS then I'll file to another nearby airport that has one, but if the weather is below ILS mins I'll probably be going further than that - and making sure I have enough fuel accordingly, regardless of the flight plan.
(Of course in the US there is no public transport worth speaking of. Airports with an ILS generally also have decent car rental though).