The big dig was a feeding trough for any construction contractor with any connections to pad their pockets on the taxpayers dime.
When people in other cities complain that raised highways are ugly the civil engineers point to Boston and say "well there's your alternative, take your pick"
I'm not disagreeing with your opinion on long term projects but don't hold up the Big Dig as an example of the way things should be.
Years later, sure the tunnels are cool but they're expensive and can't be upgraded reasonably (a problem with tunnels in general). The Big plans need to be future proofed, something you can still get utility from even if the big picture changes. Highways in tunnels under cities don't fit that (railways are somewhat of a different story IMO). An expressway that bypasses the city, maybe but a normal highway with exits, no way (IMO). The I/O locations (exits) and volumes of a highway change too frequently to invest to heavily in any particular stretch of highway.
I think the culture change that needs to take place isn't the long term outlook but more responsibility with other people's money. You can't have a long term approach to infrastructure while people are trying to squeeze every dollar out of every project. As it stands, the time it takes for something to pay for itself (monetarily, via utility or otherwise) is impractical because the time something like $project stops being "in the red" is long past the time it's a clapped out POS that needs an overhaul.
I think it's worth looking at the beginning of the 20th century when large civil engineering projects were more common for insight into the social/political side of things.