Let's see:
1) archaic #### on close firing pin
easier to open the bolt
2) came over on the ark ballistics
so did the original 30/03 round
3) defective two piece stock design
says who? it's easier to manufacture
4) springy weak rear locking action
again, says who? the L-E design is just as safe as a copied Mauser
5) obsolete rim ctg design
that's a matter of opinion.
6) non windage adjustable rear sight
depending on the model, true. however, it's a battle rifle, not a target rifle
7) impossible to convert to a decent caliber ie 30-06, 270
tell that to the guys who converted plenty of .303's to .308
All the US gun writers 1920-60 gave the above reasons why the Lee Enfield was inferior to the "perfect" rifle the M1903 Springfield.
they were slightly biased
The above opinions are not those of this contributor.