Non-mathematicians have difficulty picturing sums like 0.00014321 BTC, which would be 143.21 XBT if XBT=100 satoshi(s)
The transition would be even more seamless because people already started thinking in bits. If 1XBT=1bit=100 satoshi, it would all make sense.
I see your point, but agree with R2D221 and Jon Matonis. Don't know whether 'catastrophic' is the right word, but it would create too much confusion.
As per your example, from the small/medium business or even customer's perspective, you'll be more likely dealing with amounts ranging say between
BTC0.01 to
BTC100 rather than
BTC0.00014321. A few examples:
BTC99.15 = XBT99150000
BTC1.456 = XBT1456000
BTC0.025 = XBT25000
To me, that doesn't look much better than 0.00014321, does it?