A to-do list is a basic list; a truly GTD centric system hasn't been created yet. Some people have added the words GTD to their ideas but in reality looking through commentary (and using them), most of those applications fall way short of the intended goals.
I've yet to see a funded, well built team, with UI, IA, and mobile experts assembled to do battle on the front. Thus far it's been very small part-time teams doing what they do to scratch their basic itch.
This will be an interesting project to see what fruits.
If the argument is just that there are too many web services for managing your to-do list, I might agree--we analyzed them all when writing our business plan. But, the reality is that none of them scratch our itch. And it's not that we're perfectionists; I've never met anyone who's passionately in love with their online to-do list. We intend to change that.
However, it just seems to be a space that a lot of people have tried. A lot of the apps aren't very good, true, but others are, and it shows signs that it's heading towards being a commodity, along the lines of web mail. To do something people will pay for, it's got to be head and shoulders above the competition, and be seriously useful to companies.
http://news.ycombinator.com/comments?id=17662
And there's nothing wrong with Rails at all - quite the contrary - I use it extensively myself, and absolutely love it. Just that a lot of people, myself included, seem to end up making a todo list app with it.
