Quality over quantity is always better. It does very little good to have 500 hubs, none of which are ranking. Many hubs are poorly spun content that is simply unreadable. People post these hubs with a link to their website hoping the link from hubpages will boost the websites rank.
If you want to get your hubs looked at and ranked then you need to write quality content that people will want to read while thinking of SEO including keyword selection. That means that you may not have as many hubs as someone who just spins content, but you will have hubs that rank and earn you more.