We mod to keep up with each other, to attempt to keep the field level in play. We'll all be running around with the same blasters with all metal internals, all shooting the same distances, never having any problems, great ROF and Range, and nerfing will no longer be nerfing. The thing that attracts me to nerf, as I'm sure it does alot of people, is the creativity involved with it. It's not fun if things go right 100% of the time, and if you can't build something on your own. What makes this any different then airsoft or paintball? Sure, it doesn't shoot as far or hurt as much, but really, whats the difference?
The paintball argument is totally invalid so drop it. Airsoft is another story.
ONTOPIC : Between hoppers and slugs, range and rof have pretty much been eliminated as factors. It's pretty much come down top ergonomics and what you like to use the best. I mean my BBBB or something of the like since I sold some of my other blasters will go up with a doomsayer no problem and have done it before.
Another point is that if you don't want it on the field don't use it. Use what you want not what everyone else is. Not everyone will buy this stuff, even true modders may use these parts in some blasters but still mod stuff. Modding will never die and that's a fact.
EDIT: Rogue is living proof that premade parts don't kill modding.