Limitation of 16 bit and a general desire to learn more software.
Almost all the tracker databases are gone and everyone charges for samples these days. The main draw I had to tracking was that I could analyze other peoples tunes, patterns, samples, etc. and then get creative from there. With all that gone and general greed on the internet, I went and laid down some cash for some modern software. I ended up buying NI Komplete 6 and using Reaper as a host. I believe I could use samples from my new soft synths in Modplug Tracker if I choose to, but they generally seem to sound better in Reaper, maybe the 16 bit limitation. I do miss tracking and especially miss being able to look at other people's projects. I'll still keep it around and play with it from time to time. I am still looking at all my old xm files and analyzing my favorites for new creative ideas.
When I get time, I am going to host all my old xm files and samples on my own web site, greed free.