Because the chances of successful exploitation are much higher with Flash.
Not unless you allow Flash in Flashblock. Everyone has a kind of Flashblock today - even Chrome.
Because Flash kills performance.
Nonsense. Flash performance is much better than performance of JS, doing the same task.
Because Flash hurts usability.
Oh, really? I thought it was bad designers/programmers who hurt usability. A well-designed RIA in Flex is much better than JS/CSS/HTML mess when it comes to usability. I don't even mention support.
Because they still don't have a proper x86_64 version.
Most PC games do not have 64bit versions. Should we hate them too?
Because advertisers are abusing it.
Again, how it it the problem of Flash? And again - flashblock is an easy answer. Just like NoScript is the answer to many JS abuses.
Because it's not a W3C recommendation. Because it has DRM. Because deleting cookies doesn't delete flash cookies. Because it hurt standards like SVG and SMIL.
OSMF does support SMIL - to a much better degree than any browser out there. You do know, what OSMF is, don't you?
Because it doesn't work well (or at all) on mobile devices.
Oh... right! Here is the reason - it's not Apple. Should I start hating Java/Scala/Python too since Jobs didn't bless them either?
Because there's no graceful degradation. Because the authoring tools cost big $$$. Because the authoring tools are Mac/Windows-only.
Again - a lie. There is Flex SDK for Linux. It's free (open source). You can use it with VIM - or with Intellij IDEA, if you prefer.
Because swf files are near impossible to decompile, let alone modify.
Ever tried decompiling minified/obfuscated JS? Or looking into the "source" of GMail, which is JS/HTMLCSS? If someone wants you to have sources - he will give you the _sources_. BTW, there are many SWF decompilers out there, if you really need one.
Because they can't be crawled.
So what? It's a problem of a webmaster - not yours, as a user. BTW, GWT and many other HTML/JS/CSS monsters are not exactly SEO-friendly by default either. Any AJAX/RIA application contradicts with SEO friendliness - you've got to find a way around, and they do exist.
And again - GP question was not "what problems we have with Flash?". It was "why all the hate on Flash?". Everything has problems - just as CSS/JS/WebGL do. The more features it has, the more potential problems it can bring.