Yes, you misunderstand. It's ironic, but it's a well known irony, that being outwardly transactional about a relationship can be a losing strategy. (Example: bringing a gift to a cocktail party versus giving the host the cash value of that gift.)
Loyalty shouldn't be freely given. But it's not particularly hard to spot the overly transactional types, and it also shouldn't surprise anyone that while those tactics work for a while, they cliff out before leadership. Again, that cliff is well within the range of a really good salary. But it's a cliff nonetheless.
Your work contract isn't a relationship, you're example doesn't make sense here. My company isn't a person hosting a party, so why should I bring a gift?
I'm not disagreeing with you on the premise that work should be mostly transactional and there should be no expectation of loyalty, but the spirit of the other guy's example is that your coworkers, the other human beings who work there and have to interact with you, will find it offputting if you are aggressively transactional with them about everything all the time.
My experience disagrees with this analysis. Everyone in leadership has enough of a seasoning of cynicism and sociopathy to trivially evade the common filter for transactionality.
Loyalty shouldn't be freely given. But it's not particularly hard to spot the overly transactional types, and it also shouldn't surprise anyone that while those tactics work for a while, they cliff out before leadership. Again, that cliff is well within the range of a really good salary. But it's a cliff nonetheless.