Let's drop the absolutes, shall we?
1) Google can index it. I wasn't aware of other search engines that are relevant. I'm willing to concede that you -should- do extra work to make sure you are search engine friendly, but that doesn't rule Flash out completely.
2) Yes, text is copy/pastable. No, the experience isn't nearly as good. Yes, it's a really big deal that copy/paste sucks for Flash.
3) No, Flash markup isn't semantic because Flash markup isn't public. Then again, how much information does <DIV> imply?
4) Yes. Flex is open source and can be developed for free (http://www.adobe.com/products/flex/). I do all my Flex development with simply mxmlc and fdb, I don't use Flex Builder at all.
teej, I appreciate your response and dispelling any absolutes that I may have inadvertently spoken in. However, I don't think I spoke in strict absolutes by saying things like "As far as I know" and "Is the text always selectable & copy and paste-able?". I concede you're right, about #4 and your correction reminded me that as recent as about two years ago I used ActionScript 3 (or was it 2?) with a free compiler, as well as Flex (and I sure as hell didn't pay for any Flex compiler). Anyways, I'm not attacking Flex or Flash, I think both tools solve certain problems well. I was just trying to point out some broad issues with it that you, yourself concede exist. Apologies for that coming across as absolutes. You clearly have far more experience than I in the Flash and Flex world so thanks for your feedback.
Re:Ask HN: Why not Flex?
by allenbrunson on Thursday September 03, 2009 @06:26PM
(#803714)
the last time i looked at this issue, writing flash applets with mxmlc meant that you can't use flash GUI controls. is that still true?
As far as I know, the answer to these questions is no for Flash based sites:
1) Can it be indexed by most search engines?
2) Is the text always selectable, & copy and paste-able?
3) Does the structure of the Flash movie imply anything about the information it presents? (e.g. <table> elements imply tabular data.)
4) Is Flash & Flex an open platform which can be developed on for free?
Your argument against HTML doesn't point out any weakness in HTML itself. It does point out the lack of a standard and accepted HTML UI library, as well as a simplified, cross-browser compatible development environment for that UI library (the notable exception here may be cappuccino.org and some other, larger dev environments like WebObjects, neither of which I've used extensively).