While milli- and micro- is very simple to understand for a scientific community, "a thousand" and "a million" is understood more intuitively by Average Joe.
I hate having to agree with you, but the recent accident in Fukushima is a good example. Both mass media and the general public were completely unable to understand and communicate the difference between micro and milli - leading to headlines that there had been increases in radiation because TEPCO stated "14 microsievert" when they had previously said "0.6 millisievert" etc.
Falkvinge expressed similar views:
{amount}[k|m|u]
The amount 0.00141 could have been better written as 1.41m (1.41 millibitcoin), or 1410u for those who prefer (1,410 microbitcoin). It makes it much more readable. Readability is strongly preferable. (The k prefix works similarly for kilo and will probably only be used to buy mansions and luxury sports cars. I do not foresee a need for a mega prefix.)
http://falkvinge.net/2011/06/06/bitcoins-four-hurdles-part-two-transactions/