Just idea.

One of the main virtues of lcgs is also its main drawback - you know exactly what you get in every card pack. So part of the excitement of opening it has gone. Why not make alternate versions of cards distributed randomly within set - the same statistics, text, but alternate art, flavour and maybe some keywords not used by game mechanic? This wouldn't have impact for gameplay, but might improve collecting aspect of hobby and also help players to customize their decks and add more flavour to it. So in LotR core set you get 4 Gandalfs - but it could be art of Gandalf on cart, Gandalf raising his staff etc. You get, say, 3 space marine scouts but you could get ultramarines scout, space volwes, or blood angels scout the same stats but different art and keyword- I think it's worth to be considered especially in case of need of buying 2 or 3 of core sets, when you get 3 the same card a few times.

As I wrote, just idea. Sorry for my English.

Alternate art cards are used as tournament prizes. Reasons the same as what you stated.

The reason against doing this is it flies completely in the face of the LCG philosophy - NO MORE BLIND BUY.

No, it's not as bad as rare-chasing where rare cards are actually more powerful; but it's an artificial way to inflate demand and creates an unecessary secondary consideration. Plus having random alt-arts seeded throuout otherwise standard distribution has additional cost implications for FFG in terms of production and packaging.