It also helps that linux had a much better 32-bit compatibility than windows did. Not sure why but it probably has something to do with legacy support windows shed moving to 64-bits.
Linux was natively written for 32-bit CPUs, so they had no legacy cruft or software to support. IIRC, the first 64 bit port of linux (I think to Alpha?) exposed a lot of code that needed to be rewritten as it assumed 32-bit and/or x86 specifics.
