You know, before I tried Flash programming I would have agreed with you. But Flash has been painfully awkward every time I've tried it (for programming).

HTML5, if learned from good resources, using good tools, is much nicer for the programming side.

I'm probably making an ass out of my self now but: For the love of god, please don't learn Flash! People learning Flash have given birth to the worst parts of the web. There's a reason why everybody wants to get rid of it.

You can't complete non-flash projects by yourself?

I think what radley means is that Flash is an all-in-one solution, whereas to finish a non-Flash project you would have to master HTML, CSS, a back-end web framework, and perhaps some JavaScript as well.

I suspect the point is more that Flash enables one to tackle both code and design with a single toolset.