Remember Shield skill is important when actually using a shield and that shields are very heavy.
The problem with shield using at the moment is that the weight of the shield combined with generally lower strength means that shield users are confronted with the full speed penalty due to weight only slightly countered by their short weapons.
Making some of the "clumsier" (use in lack of a better word) shields more accessible is a good idea but, decreasing the force-field generated by a shield when its user is poorly skilled is a necessary precaution.
Some shields like the board shields or fur covered kite shield should have only say 1 or 2 shield skill needed. This would be great for level 29 "finished" builds like 18/18, 21/15, 24/12 ect that have those few extra points or pure strength builds that keep getting shot and are not phased by gear weight.
Remember with low shield skill using a heavy board shield would be very slow and leave the head or feet of the user exposed.
Note: Restricting the use of shields by athletics biased builds isn't going to help the problems we are facing in the archery area right now.