Why should people move to IBM? Remember, their POWER processors were also vulnerabile to both Meltdown and L1TF - IBM systems are probably the only non-Intel servers that were. (Note that I really do mean non-Intel here, since AMD wasn't affected.) Their z/OS mainframes were probably vulnerable too but they don't release public information security about them. The only reason no researchers had discovered this is that IBM hardware is too expensive to test.
Red Hat released info about z/OS mainframes, they're also vulnerable to Meltdown as well as Spectre. ARM also has one new design that's vulnerable to Meltdown, and everyone has Spectre vulnerable designs.
