In some ways, I can actually understand why Apple would hate Flash. The Flash plugin on OSX is nowhere near as good as the Flash plugin on Windows. Now Adobe will counter they spend a disproportionate amount of money on Flash for OSX, i.e. they spend more money per OSX user than they do per Windows user. So what? There are a lot of other technologies out there that work equally well on both Windows and OSX. Just focussing on web technologies, Firefox and Chrome on the Mac are very comparable to their Windows versions. So is the Java plugin. Some other products, like Opera and Skype, tend to trail in terms of features on OSX, but not in terms of quality. If these other companies can do this, why can't Adobe? It's obviously either lack of ability or prioritization. My guess is the latter, and hence you must expect hate from Mac users. And from Apple. So it should not be so surprising that Flash is left off the iPad, iPhone, etc. If Adobe really wanted to get Flash on those devices, an obvious first step would be to make Flash on OSX as good as Flash on Windows. That is something that Adobe can do all by themselves. Instead it seems like they would rather publicly bemoan their exclusion on the iPad. Now is there a guarantee that if they improved Flash on OSX, Apple would care? No, of course not. However, there is no way they will get on those devices without this first step, IMO.
Ok, so Mac user hate for Flash is understandable. Along the same lines, I would guess that Linux user hate is also understandable. That is, if there were actually any Linux users out there. I digress. I see a lot of hate from developers. What about that? That one is not so easy for me to understand. As a web developer, Flash has been opening doorways for me for a long time. Need to cache 30 KB of data on the client? For a long time this was impossible unless you used Flash (or maybe Java.) Need to make a cross-domain call? That is still generally impossible from the browser, unless you use Flash. Need to show 2D/3D graphs and visualizations? Again, this is still generally impossible, except through Flash. Oh and video... The only way to show a video that can be played on all of the top five web browsers (IE8, IE7, Firefox 3.5, IE6, Firefox 3.0) is to use Flash.
So back to the original point. Why do developers hate Flash? It certainly enables them to do more stuff in web applications. Even if that list of extra features is being shrunk by the HTML 5 monster, it's still there. So shouldn't they love it? Well, you would think so, but they don't. Here are some guesses as to why:
1. Expensive tools -- Most of the tools used by a lot of developers are free. The Flash authoring tools are far from it. That can be annoying. You have to throw down a lot of money just learn something. That's not cool.
2. Bad tools -- At least from a developer perspective. The Flash authoring tools have historically been aimed at designers. That changed with Flex Builder/Flash Builder, but the damage was done. Also, those tools were aimed more at application development, which largely seemed like a waste of Flash.
3. Back to the Mac -- A lot of developers use Macs, and we all know about Flash on OSX...
4. Accessibility -- Unfortunately this doesn't mean much to most developers. But it should. I must admit, that a year ago I probably wouldn't have listed this. However, as I have learned more, I have learned how Flash is such a huge problem for accessibility. This is actually one area where HTML 5 really shines, with the inclusion of the ARIA standards.
5. Design envy -- This kind of goes back to #2. Flash has had all the awesome capabilities for years, but they have largely gone untapped in web applications. Maybe by playing to designers all of those years, Flash has earned enemies. Imagine a developer being asked to scope some radical web feature. They give a typically large scope for it. His manager turns around and gets a designer, a freakin' designer, to do it in half the time.
What have I missed? Why do web developers hate Flash so much?