If you want your MPEG2 DVDs to work on an NTSC monitor, they'll have to become 60i at some point along the road anyways...whether in camera by shooting 24PN or by the player, as it adds the 3:2 pulldown automatically to your 24P MPEG files.
25P files won't play in NTSC, so you'd be converting them anyways, and the resolution boost of PAL vs NTSC becomes useless when displayed on an NTSC monitor.
Basically, you'd have to re-work your footage to *become* 24P, so that you can then convert it to 60i, *and* there would be no resolution increase in the end. It's just not worth it overall...
Simpler answer.. because Pal is a pain in the ass to work with in North America, because unless you know your only going to film or the web for every single project, your gonna hafta goto NTSC and the process to get PAL to NTSC is just not fun.
My DVD player actually plays PAL DVD's fine, so it must internally convert. Although it is such a cheapie to have a converter inside.
I remember with old PAL VHS tapes chroma all messed up. Just haven't seen that on any of the PAL DVDs I buy. So I figured, hey why not master with PAL even in the US.
If yours does, thats great, but most people's wont...so you'd be converting for them anyways. Unless you're the only one who'll be watching your movies