I think that tournament player overstate how important they are to the business of the game... I'm fairly sure that the extra stuff they will sell to accommodate tournament players is just a drop in the bucket in terms of sales. I don't think them having to buy extra stuff is much of a sales strategy at all. If players buy cards online that hardly is money in the pocket of FFG either. Allot of collectors just buy the ship to sit on a shelf and they then sell the cards.
I also think there is a huge difference between using a home made ruler (which I do by the way, made some nice wooden sticks) and a copy of a legal card. If someone cheat and change the text of the card they will be disqualified I guess anyway. I also guess people use old outdated cards in tournaments as well so I fail to see how using a copy of an old card make much of a difference. The cards you use in a tournament is only for reference, there are not more cards in the game that most people already know what they all do anyway, especially people that attend tournaments.
In my opinion not accepting printed cards is just a cheap way to exclude people from official tournaments, having the plastic ships should be a requirement enough. The rulers I can get behind that they need to be an approved model, but lets not get overboard there either. Even the card stock rulers will vary between games as paper will shrink and twist over time and they will not be more exact than most home made stuff anyway, at least if they are done with thought and care.