I had no problems putting my headers in on the passenger side. Ive done swaps a lot. And from experience I've never had problems with the pass side, do the jiggle thang. As for drivers side, I always just unbolt the clutch cable, move it, and they slide right in / out.
with my mac equals it was a pita. i was doing the clutch at the same time so the tranny was out, and i installed from the bottom. but i still had to remove the steering shaft to install the driver side. the passenger side just slipped up.
This is just a case of someone giving up too soon, or too inexperienced to realize that not everything just drops in. Who gives up when the valve cover is in the way?? Youngins I swear, but its all about learning.