Things must be simple if you only go to amazon.com.
So dismissing browser performance problems when Flash is embedded (I'm not even talking about playing) by saying "I don't need it - you turn it off" is not a solution. Also, disabling Flash is not exactly one click operation... You seem to not attribute much importance to usability, user experience and other such trifles, but they matter.
And even with Flash disabled MicroB is not fast enough, it occasionally freezes for split seconds while loading pages or scrolling. Don't get me wrong - developers did an admirable job given MicroB's origins in Firefox, which is not known these days for speed and good memory management. But it's not good enough just yet.