I'll take a general stab in the dark -- you're planning on selling (leasing, licensing, or whatever the technical term is for letting the person giving you money use it without having any real rights to the program).

By switching to a language that you can compile, you ensure that people can't just look at the code, and they have to either pay for support to have problems fixed, or do a whole lot of work with a decompiler (which of course, you'd make sure to prohibit in your licensing terms.)

Am I close?

(it's the only reason I can think of that you'd spend the effort to take perfectly functional code, and accept the cost to rewrite the whole thing in a different language, and not be concerned with exactly what language you're going to)