For my two pennies worth there are a few good reasons to have a blog as opposed to writing for HubPages.
1. You have full Editorial Control: If you are writing on your own blog you are not tied to the limitations of HubPages. You can post what you want, within reasonable boundaries, most hosting services have rules on what canbe posted on sites but they are very unlikely to pull your content because you have been idle for a few weeks.
2. Hosted Blogs are very inexpensive these days. A blog on Go Daddy or Host Gator can be had for about $6 per month.
3. You can monetize your own blog and NOT share your income with HubPages. When you publish on HubPages all ad revenue and revenue created by people viewing your work is shared with HubPages. Also items sold on your Amazon and eBay links are shared with HubPages. Fine you are happy sharing your revenue for free hosting, but revenue sharing is not really free, and if you are not a member of Google AdSense scheme you are giving your revenue to HubPages for free.
Having your own blog may not give you access to Google AdSense, but there are other cash per click options out there who might be more suitable fir your content.
4. You are responsible for your own reputation. As HubPages becomes seen as a place for poor content and marketers and spam your reputation becomes tarnished. With your own blog, you are the controller of your own public persona. You can keep your own reputation squeeky clean, and wholesome.
Ask yourself if you may reach a wider audience and make more money, being your own independent blogger.
It does take some time, two or three years to start to build a strong blog, so its not for everyone, with perseverance though blogging can be much more satisfying, publishing for yourself rather than for another organization like HubPages.