^ Laziness. But if I were to close every thread that's been discussed, we wouldn't have anything but mega threads. If multiple threads of the same thing pop up, I merge/close, if not, it gets to stay. The OP's thread title is misleading in either case - read his post.
But yeah, OP, this is fairly basic and it is like comparing apples to oranges. It's a preference thing. Each strain has different properties, like having higher CBD/N to THC ratios and such. Often, the low grade or Indica strains will have a higher CBD/N count or concentration, leading to a more stoned high, less sharp, more foggy, and probably tired or couchlocked on the come down. So yeah, while THC is needed for CBD/Ns to have an affect at your CB1 and CB2 sites, it's not all "just THC". Sativa strains likely will produce a more mind-fuck high, which can result in paranoia for some.