What I'm surprised about is how nintendo blocked the flashcart before release. Was the exploit that gateway used obvious or some shit?
Obvious in the sense that it would be the way any first blush attempt at a flash cart is obvious then yes. They then get to attack it from the same mindset and think "if I am cloning a game cart" and "if we are to use the same ROM images that are already floating about".
Now whether Nintendo has a definitive solution or not remains to be seen, it could go either way really though knowing Nintendo's previously lax attitude towards proper patching (and ignoring them apparently upping their game a tiny bit) I am guessing it is probably something quite basic. Going back to the "not a 1:1 clone" stuff from earlier the trick is to ask what makes it not a 1:1 clone -- for some games the original DS checked to see what the cart returned if it read below 8000 hex as flash carts originally responded with the exact data where a proper cart would not. The number of failure points for the gateway people is uncountable and the number of ones viable for use in a check is only marginally less so I can not really elaborate further.
There are still enough people who want to use Homebrew
Back in the day as it were that might have meant something, now everybody can code for android or such like what does it matter?