I would argue that it's not a good idea to do this for all branches by default. For example, we do the opposite for 'master', we force merge commits (--no-ff)

I would argue that it's not a good idea to do this for all branches by default. For example, we do the opposite for 'master', we force merge commits (--no-ff) on master/integration branches but use pull --rebase on feature branches that we share.