In my opinion, Stephen Bannon has no place in a White House administration. For many years, he presided over an alt-right news outlet which incited hatred, promoted white supremacy and racism, and encouraged hate groups. By firing Bannon, Trump would send a message that he does not tolerate the ideas Bannon's news outlet stands for.
Bannon is not the right man to counsel anybody. His racist rhetoric is extremely dangerous and he does not belong in the white house with that in mind. It is so blatantly racist and that is something we don't want our country to be represented as. There should be a more neutral person chosen.
Stephen Bannon has shown to be a racist and unfit for public office. The public would not want his influence over policies. It also appears as a negative for Trump to associate with Stephen Bannon and depicts poor judgement if Trump keeps Bannon close as an advisor. The selection of the Trump's cabinet and advisors is a true reflection of Trump.
Bernie Sanders doesn't get to impact Donald Trump's administration because he lost. In fact, he lost to the person who lost to Trump, so why is this guy even in the news? Although Stephen Bannon isn't a great choice to have any power in the country, it's Trump's decision to make, and not some old socialist from Vermont's.