Flash always have security issues and Adobe do their best to fix them.
On the consumer side of things, flash is not so bad. Sure search engines couldn't read it but there is amazing content generated through it. The content is,what matters and unfortunately the Web is littered with abusive flash objects auto playing videos, audio, full screen ads and those won't simply go away with flash.
At least with flash I can easily disable it. But those auto playing html5 videos and audios ads are just as annoying. Now I need plug ins to disable native capability.
It's only a matter of time until all ads move to the medium and we find ourselves complaining.