Why in the U.S.A. the P.A.L. system was never itroduced?

[Telecolor 3007]

Why, after the introducing of the P.A.L. coulr televison system in Europe, the P.A.L. was not introduced in the U.S.A. In fact, P.A.L. is superior to N.T.S.C.
They could treyed to introduce the P.A.L. on the East-Coast states with big number of inhabitants, like New York and Pennsylvania, to see if the public like it (thay also could manufactured colour sets that could work bouth in P.A.L. and N.T.S.C).