Well, its pretty simple. Why should people be against open-sourcing it?

I think 90% of those who are against it, are against it, because they want to forget flash and never see it again.

So somehow, they must have made so bad experiences with flash, that they do not want to get it for free or even someone else to get it.

So you next question is probably: What could have been such a bad experience? Probably not a just one. From my own memory:

Good experiences with flash:

- youtube, etc.: Flash was overcoming the codec problem we had in the past. By providing a minimal set of supported codecs it was setting a defacto standard for video streaming. But that problem is solved today.

Bad experinces with flash:

- Flash menus (please install that macromedia plugin before you can actually use this website)

- Flash menus (please wait until this uber cool animation finishes to render before you can click on that link)

- Complete 'websites' in flash (Please install that plugin before you can see if this website is of any use at all)

- Header logos with large file sizes, as they are animated like hell

- a laggy computer just because some website embeded a flash animation which uses all of your CPU power

- Contact forms which disallowed copy and paste.

- Websites which you could not find again because the search engine could not find them.

- decisions about being vulnerable vs. actually seeing flash content at all

- tracking cookies beyond normal cookies

- extra applets which are there just to make sure you are a real browser.

So I think nobody has a real problem with those gift cards or the games. But given the history of flash we would better not receive a gift, just to make sure we will never have to experience those moments again.