A cursory glance at that article suggests that the synopsis of vulnerabilities is not necessarily inaccurate. I didn't really see anything I could enthusiastically disagree with right off the bat.
That doesn't have to be a bad thing though!
In fact, I think that you will find it reasonably safe to state that "all" blogging and CMS platforms have suffered from vulnerabilities throughout their histories. WordPress and the community at large seem to be very, very good at recognizing and responding to those issues and updating or patching is usually a quick process. The applications on which WordPress and many other publishing systems run are constant targets for exploitation themselves. The good thing is, as the community grows and the software matures, developers will continue refining things until in theory, the best possible combination of stability and features can be reached without compromising safety. And, of course, third party items such as themes and plugins, as well as the rapid introduction of new features, always opens the door a little bit for new opportunities to exploit.
Assuming the WP is secure (and I believe it is)
I do too. In as much as any web application can be secure. I think the best thing you can do is stay in touch with the issues, and make sure you do everything you can to secure your site. That means staying updated and learning how to best manage your web space and server, as well.
There will always be people of questionable intent trying to do things they shouldn't be doing with other peoples web spaces. I doubt that will ever change. I always take wikipedia with a grain of salt. I use it as a quick link resource more than anything else.