Banks and other companies are not abstract entities to the people doing the negotiations; they are other negotiators and people like you. Being nice is a good way to improve relations with the other party, but this can often be short-sighted or even self-serving if you aren't taking into account the best interests of other people not present in negotiations; plenty of government representatives play nice with their donors to secure future campaign money, and/or ensure a cushy position with that company after leaving office, for example.