Why aren't SD card 'contacts' uniformly placed?
Solution 1:
The power and ground pins stick out further, so that power is applied/removed before/after the data pins are connected/disconnected.
Pins 8 & 9 were added to the MMC format in making the full-size SD format. So there was not room for a full-sized 8 (maintaing backward compatibility), and perhaps they learned a thing or two about applying/removing power first between MMC and SD (or about making it cheaper without an extra switch if they extended the pins).