You're mad because they haven't corrected a problem that doesn't exist? It's not a problem it's a feature of the device? mkiker2089 does a nice job of explaining it above.
If it bothers you this much you might want to buy a smart power strip that will power off anything plugged into it when the TV is turned off. Or a remote control power strip.
Our night lights with sensor use more electricity per day than the Roku streaming 4 hours and being in standby for the rest of the day.
A couple of years ago, I went over the house usage when we did use about $180 a month but last month the bill was $80. As you said, a Master/Slave power strip is golden for each hub of power usage in the house. Turn down the refridge/freezer and only turn it up if you add a lot of new things. And shut off the computers when you are not using them. Simple rules and yes, our Roku is not a M/S strip because it is only it and the tv so there would not be a saving by buying a strip. Besides, it would have to boot up every time.
Edit: Since I did test, by setting the clock on the microwave over leaving it blank, you just added a 1/4th of what the Roku is using by setting the microwave clock.