I think people (myself included) have read a little too much into this but unfortunately it will be a while until we know the truth behind their plans. We'll at least have to wait until the first firmware update to find out if they are actively bricking devices, and even long after then there will always be a seed of doubt.
To me it is an issue of consumer rights and anyone who agrees with this practice because it helps prevents piracy is foolish. Yes, these cards can be used illegally but that it not their only purpose. You know what else can be used illegally? Your computer. A gun. A boxcutter. A pencil. I realize the analogy isn't perfect (although the computer example is pretty apt), but the fact is that you shouldn't punish people who buy these cards. You should only punish people who buy these cards and use them to pirate games.
You could also argue that using a flash card to run alternative firmware, even for the purpose of innocent home brew, is against Nintendo's terms of service. However that is also an issue of consumer rights, namely the right to actually own your freaking hardware and not have it on extended loan from Nintendo. The Library of Congress added an exception to the DMCA for jailbreaking iPhones, how is this any different?