Nothing in your argument deals with the political affiliation of companies and their management. You might have an issue with companies not having enough diversity but that has nothing to do with their political standing.
Your argument might have had merit if you bothered to cite a study that shows that correlation (seeing as this isn’t common knowledge). From where I’m standing, it’s hard for me to just believe you, considering the race/ethnicity of the CEO of Google.
As for not paying interns: many companies work with this frame of thinking where they equate interns with free labor. Which, if we’re honest, has nothing to do with politics and a lot to do with bad business practices.