Well, I can only speak for myself, but a brief tour of my TW career will probably illuminate a bit...

I first "discovered" the TW series through the "Time Commander" TV shows, and was instantly hooked by the promise of fighting those classical era battles they featured. I eventually discovered the series was based on RTW which hadn't yet been released - so I got the nearest that was available, MTW. When RTW was released I found my PC was too puny for it, but then I discovered Hellenic:TW, and subsequently played my first ever MTW mod, which totally blew my socks off. I got started in modding by first doing some additional graphics for HTW, then I worked on a "fix" for the HTW Bronze Age scenario which wasn't quite working in the release.

After playing this for a while I got more interested in the history of the era, and as I read more, the thoughts running through my mind were along the lines of "The Punic Wars are fascinating.... wonder how it would play in MTW... gosh, I never realised the Hittites did that .... wonder how it would play in MTW ... etc etc etc"

In the end I just had to make a whole new mod, and Ancient: TW was born. Largely for personal satisfaction, but it seems to have acquired a few other followers as well. In the middle of all this I did eventually upgrade the PC, tried RTW and found it severely wanting, especially the tactical/battle AI. Hence I decided to stick with the MTW versions of the era, filling holes myself as and when I found them.