Why it's in PAL? Maybe because I'm from Finland, and we use PAL here, and I only have a PAL tv and a PAL Atari 2600 jr.
Actually, it works 100% correctly in Z26 AND Stella, I couldn't see any slowdown or bugs or anything
The main reason is that we usually grind EVERYTHING out of the extra rasterlines thus being able to show more stuff on screen. Having more time in the kernal part also enables more code executed there.
And to answer to your criticism, YES, we are planning on converting everything to NTSC, because well, you said it too, we want a greater audience for our productions! I'm not PAL crusader or anything, we have just made due what we have available.