Re: Why?
You can't just buy SPARC boxes off ebay and swap core parts these days - if your motherboard, memory riser, fan board or that sort of stuff breaks you need a support contract and an engineer on-site to make them talk to each other again after replacement, and that's kit that is 7-10 years old.
Anon cos I'm in the middle of procuring replacements for our T4 servers before they fall off the support list for 11.4...