Normally small business owners, personnel bloggers, SEO guys, and non-profit websites use cheap web hosting. It also attracts scammers and spammers.
As you know, a lot of small websites share the same server in cheap web hosting company. That can lead to resource bottlenecks and other problems associated with sharing IPs.
If you have bad neighbors, your websites will not be SEO ranked higher and your emails maybe be bounced back or into spammer folder.