I love how 1 MB of RAM is 1048576 bytes but 1 MB of storage is now 1000000 bytes of storage
Makes perfect sense. RAM is addressed with a N address lines, giving access to 2^N cells, so base 2 makes sense. For everything else, base 10 makes more sense, especially when you're talking about speeds.
simply because the hard-drive industry decided that they could make more money by using the same term
Really... You do realize that disk sectors, file systems, etc. are all Base-2? Base-10 makes no sense whatsoever. In fact, there is a movement back to base-2 for storage sizes as the industry moves away from magnetic media to memory based storage (SSD).
I would argue that using Base-2 vs Base-10 for CPU speed is irrelevant. CPU speed is only useful when comparing CPUs that have the same architecture and are in the same family. Even then, people only look at which one has the higher number. If it was a useful indicator of processing power, then we wouldn't use CPU benchmark applications to compare between Intel and AMD CPUs or between different Intel CPUs, etc.
They didn't make more money because everybody was doing this.
If you take a chocolate bar and make it 10% smaller but charge the same price then your margins and profits go up. That's what the hard-drive manufacturers did by simply changing the definition of MB. Granted, it was a one time thing. But they did get a nice surge in profits around the time that they made the changeover.