Yeah, and if we took all the pretty pictures off all the text would be faster.
Silverlight is what allows Netflix to stream to a computer. I think Hulu uses Flash. Yeah, they use a lot of horsepower on computers, but it's WELL WORTH IT.
You seem to be confused as to the alternatives out there. Just because you are ignorant of the alternatives doesn't mean they don't exist. Flash and Silverlight are resource hogs, you can justify it all you want but it doesn't change the fact that there are more efficient ways out there. Educate yourself before you go out and use sarcasm.