Because most of the gravy is in getting those things wrong. The bank or the government will find more money to keep the work going.
I worked with a GC who bragged about tripling the budget of a highschool build. If you are doing large projects the only way you're going to win is to be way off on bid day and to be good friends with the people who figure out the financing.
Yeah this. One of my friends is a PM for mostly government contracts. He also gets serious commissions for any mid project add ons so they're incentivized to low ball and win contracts then get customers to pay more later.
I worked with a GC who bragged about tripling the budget of a highschool build. If you are doing large projects the only way you're going to win is to be way off on bid day and to be good friends with the people who figure out the financing.