No problem.
With multiarch support being mainstream in linux now there isn't anything particular to be gained by MC itself being a 64 bit app and the ability to run on some older hardware would be lost if we did a 64 bit only version.
At this time, the build process isn't as simple on linux as it is on Windows and OSX so the time required to maintain 2 builds (as well as to get a pure 64 bit build running properly) hasn't seemed worthwhile yet especially since there is still a lot of other work to do on the linux version, missing functions, gui weirdness, etc..
