I think you have this backwards. I can't be sued unless I implement the patented idea in hardware.
In that state of the world, if they patent the hardware solution, I don't care. I can still implement in software and I have a legal workaround to avoid infringing. I'm driving the truck through the hole.
In that state of the world, if they patent the hardware solution, I don't care. I can still implement in software and I have a legal workaround to avoid infringing. I'm driving the truck through the hole.