I was about to say that. Rights to source is determined by the contract. To my ear, someone who hates Flash because their devs won't cough up source is someone who (1) doesn't code (2) doesn't understand the law, and (3) made a bad contract and blamed the flash dev, and now is taking out his bitterness about the experience on Flash as a platform. Which is ridiculous.
As a coder who doesn't, and never will, sign works-for-hire agreements, I'm the model of a dev who won't give you the source if you fire me or treat me like shit. In one incident, a customer who paid $100k for me to develop a flash app, then sold it to News Corp without mentioning to them that they didn't actually own the source for it. News Corp had, legally, every right to reverse-engineer that app; moreover I actually gave them the source because I'm a nice guy, but I stipulated that they couldn't repackage it without my assent, and that the classes which had been developed outside the project at hand (some of which had been coded on other customers' dime) were not for resale at all; and that in no way could they claim ownership and try to prevent me from reusing any of it for my own purposes. News Corp then hired a team of coders, paid them in excess of $300k to try and reverse-engineer my code. When that failed, they called me and offered me $50 an hour, half my regular wage, to help them, if I would just sign their NDA, which happened to include handing them eternal rights to everything I'd ever done. I told them to fuck off, and the project died a week later.
But more importantly, anyone who knew what they were talking about and who wasn't just a frat boy shilling for HTML5 because that'as what douchebags talk about at Q's on Fridays would know that technically, there are 101 decompilers for Flash, and legally, you can decompile code you paid for and have someone else edit it as long as you aren't reselling it, even if you didn't have the coder under a works-for-hire agreement; and morally, if your coder is telling you to piss off and not giving you the source then you're probably an asshole who deserves it.