The problem is that software was never dealt with properly by the Courts or Patent Office. For years they refused to even consider an application. Thus, they compiled NO prior art. Then when the law changed to loosen up eligibility, there was no prior art upon which to base a rejection.
As for Microsoft and the others, for years they ran over the small competition. Leaving a trail of defunct companies. Those companies did not have the means to fight prolonged patent infringement battles. But they left their patents behind. The trolls grabbed those patents. In a way, and I am no fan of trolls, they made sure the patents ( of those stepped on companies) came back to haunt the Microsoft’s of the world.
Back to patent reform, there were a zillion ways to reform the system to deal with the trolls and lack of prior art. But instead congress did it’s usual. They allowed themselves to be bought and paid for by Big Tech and passed “comprehensive” reform that gutted our patent system.
Not to worry, China hasn’t gutted their system. They are doing quite well.