In the mid 1900s manufacturing was a growing industry. And in a growing industry, growing fast matters much more than being frugal.
In order to grow fast, these manufacturing companies needed lots of workers. So when the workers banded together and asked for more money, the attitude of the executive was like, “sure, give ‘em whatever they ask for, so long as the new model isn’t delayed”. This lead to companies overpaying for workers.
Right now, we just live in a time when the fast-growing companies overspend on different things. Like servers.