bjadams that may be true, if you want an export for windows
without as much overhead/functionalities or good performance you are alway free to try to use alternatives like this one:
I wouldn't say it's a curse, of course, the SDL for example is really minimal in it's size compared to NW,
but the more functionalities/freedom with the easiest difficulty you want, you have to pay the price in it' size.
Not everything can be perfect, but in general, it's still a long way to go for HTML5,
you can expect some awesome things i think in the coming years looking at the speed of development of new things for it now and then.
Especially considerating the big companies are beginning to use it more and more.