Microsoft did not destroy Be, its own incompetent management did (with a bit of assistance from AT&T when it decided to discontinue the Hobbit chip.) Be first tried to create a new hardware platform, then tried to be an alternative OS for mac hardware, and finally headed towards the wintel world. By this point it was far too late. Given the space left for growth in the x86 line there was no need for multi-core in the late 90s and the cost of going to a bigger chip was far less than the cost of adding all of the additional motherboard support for lashing together multiple copies of last years CPU.