Okay everyone, fight's over from the onset... Live2camp already answered his own question and everyone missed it.
If TLDCN/RTN already covers 86% of the user market and I don't think they have it all just yet, why would they now spend another 100% of the development cost for another 14% of the market of only which they'd only get a small portion of it, too? Do the math. Then, since there are emulators to cover the other 14% and there's no cost to them for that, again, where's the market sense and thereby the cost sense for providing this effort?
Don't forget the big reason. TLDCN & RTN were written for a document/magazine company, by this software company (UnderTow Software). Trailer Life "contracted" (not has on staff) a software company to do this program for them. The cost needs to remain low to maintain a good profit margin. ADDING Mac support is expensive for the return on the investment.
While I think it was called upgrading to a Mac, you aren't upgrading. You are changing!!! You don't upgrade to a $10,000 Rolex, then wonder why you can't have a digital display like your Casio did! You changed to a Rolex not upgraded!!! For a MAC, if you want PC apps you buy an emulator. For a Rolex, if you want a digital display, put the Casio on your wrist, too.