Basically, for the price of the Shuttle program, the US could've built an entire SERIES of space stations vastly larger than the ISS, because one Shuttle launch cost as much as a lunar mission, and could only loft 20 tonnes of useable cargo.
It is a bit more complex than that.
Technically, they did some research about making a non-reusable thing
to place instead of the shuttle to lift cargo instead of pointless crap that comes back again. Using engines that reached the end of their human-rated life they could have sent up at least 3-4 skylab-sized stations (one at a time
) at an interesting low cost.
The point was that none with decisional power really gave a shit after the pissing contest with the reds was won.
To put this in context, the saturn V stuff was scrapped for cost reasons (lololololol), and none had the guts to do a shit about it, the shuttle program was approved only because NASA (and maybe the president) decided to tell bullshit about lower cost of this new program.
There was very little way to convince the congress that another rocket would cost less than Saturn V, other than drop the word "reusable" here and there and hope the chimps in the congress get fooled by a radically new design and some creative finance.
So the choice was "no more space access AT ALL or blatant fraud to mantain a token space access". "Decent architecture that would allow creation of space infrastructure and eventually colonization of solar system" was not
an option before as it is not an option now.
Hell, they terminated even the fucking inflatable living module
program, that would have obvious use for less-launch-intensive space stations for the usual bullshit reasons ("too costly" even if there is a private company that planned to make the first products for 500 millions total).
HOW will space colonization bring an economic benefit?
By selling stuff to colonists that leave Earth and are ready to do some sacrifices for their dreams that will likely crash and burn.
For gold rushes worked like that if I'm not mistaken. The ones that made the REAL money were the supply-sellers, not the gold miners.