Jsin nailed what I was trying to get across.
Here is the thing, normal wear and tear on an SSD from most programs isn't an issue.
However, Minecraft reads every block when you come to a chunk. A chunk is (16*16)*256
No granted most of that is compressed down, it is not actually reading every block, it is reading a compressed version.... Unless you are actively building and interacting with that chunk.
In Vanilla MC this isn't much of an issue. In any modded pack though, this is HUGE.
One of the main modpacks is Buildcraft2, that allows the user to build and place an automatic quarry. The quarry actively forces the chunks it is placed in to stay loaded, and then auto breaks and collects each one to dump into chests in another chunk. This is while the player is elsewhere doing whatever. That is a huge number of writes/ reads for an SSD.
This is why most companies will never run Databases from an SSD, you always use some sort of spindle drive. The data access, and wear and tear is just easier to manage currently.