Technical reasons mainly related to dependencies: MCPC+ heavily depends on the SpecialSource remapping tool developed by md_5 for NMS plugin support; he kindly offered hosting on his Jenkins so MCPC+ can automatically rebuild when SpecialSource is updated, pulling from the latest Maven snapshots (with MCPC-API as well). No anti-technic conspiracy here, promise. In fact we were originally going to keep both the build.technicpack.net and ci.md-5.net Jenkins active for MCPC+, and had them both online for a while, but because of the way the builds are kicked off the build numbers would necessarily desynchronize, resulting in confusion. The original hosting at Technic is very much appreciated but using md_5's makes more sense going forward.
So be sure to grab the latest builds from http://ci.md-5.net/job/MCPC-Plus/ from now on, wouldn't want any bug reports from old builds since fixed, the new builds are much better =)