I think it's getting Bits and Bytes a little mixed up. You can expect about 1/10th speed?
Most file transfer dialogs I've seen ("real world"?) display transfer rate in Bytes. Advertisers use bits, that little marketing wave can actually explain the speed drop to 1/8th of the "advertised" rate.
I believe the article takes that into account and describes the speed loss you'd see over and above the "loss" from conversion. (it does use bytes somewhere in between, so you know they're aware of the difference)
That's not what this is about. After converting the manufacturer's bit speeds to bytes or after converting every other tool on the planet's byte speeds to bits, you still get lower performance than the packaging claimed.
Most file transfer dialogs I've seen ("real world"?) display transfer rate in Bytes. Advertisers use bits, that little marketing wave can actually explain the speed drop to 1/8th of the "advertised" rate.