I totally agree with you.
AdSense on a Web Hosting Company's homepage is extremely unprofessional. It almost seems like you're desperate for money. Adsense displays relevant ads based on the content, so what do you think you are going to see? Ads for web hosting, of course.
If you want to use AdSense to make some profit, simply make another site and invest some time into it, get it established, and slap adsense on the top.