It's all part of getting along. If feedback that ideas are bad is not welcome why would you want to give it?
Being nice to everyone including your boss elimates a lot of problems.
Taking credit for someone elses work gives you additional power over that person and them additional responsibility when things go wrong.
Your boss will take credit for the departments work, his boss will do the same, her boss will do the same the vp will do the same. Their job is to get everyone under them to meet someone goal set by above. Everyone is taking credit for everyone elses work all the way up the chain. We do this as parents my child made the honor roll you might tell a friend knowing it reflects on you.