All true, but there remains the problem of a symbol that's already assigned to Bitcoin; BTC. The dollar, USD uses $ for each and every amount. It wouldn't make much sense to have two symbols for Bitcoin; the already famous BTC and another one for "Finney." Each price now and in the future is written in BTC. Do you want to change this?
BTW A cent is in fact a dollarcent; for me a cent is a Eurocent.
I'm sure the metric prefixes and symbology aren't going to change, but perhaps informal or colloquial terms will eventually emerge for the milliBTC and microBTC units. For example, we all agree that a "satoshi" is 0.00000001 BTC, 0.00001 milliBTC, or 0.01 microBTC, without needing a new symbol for it.
In marketing terms those metric prefixes sound very small and evoke the suggestion of dealing with tiny little fractions. Though I'm not much of a salesman, but arriving home and telling your girlfriend or wife, or both, you bought 100 milliBitcoins for $80 would not impress her and make her think of you making a great investment. The story turns 180 degrees when you tell her that you bought 1000 rootBitcoins for $80, doesn't it? Additionally there is no need to name each increase by the factor ten/hundred/thousand; nobody writes 1 gigaDollar or 1 megaDollar or 1 kiloDollar or 1 deciDollar.