Hahahahaha...I'm sorry if I sound mean, but I just had to laugh. Of course, sometimes it's understandable to mistake things or not know the terminology, but I just had to laugh. Yes, Ghz is faster than Mhz.
No, it's actually the consumer's fault for reading the fine print. Hard drive manufacturers actually put that disclaimer in the back in small letters, so you can't sue them over not having the actual amount of space.