There's no doubt that other countries get screwed when it comes to game, system, and peripheral prices. As an American I'm sorry to hear that, and lord have I heard that for many years.
I would guess (I have no actual idea, mind you) that the difficulty lies in setting the initial Point -> $$$ conversion rate. While they potentially could change this all across the board, it would still result in a few problems overall:
(1) You can presumably change the point values you can buy fairly easily through XBLive, but that requires people to have a credit card tied to the account. Unfortunately, even in the US, many people are unwilling to do this since they don't have access to a credit card or do not want to worry about their box (and card) being stolen.
(2) While the electronic end could potentially swap point values and costs easily enough, the physical market is another case entirely. I'm not sure about the profit margin (if any) on point cards for various systems but considering the dearth of sales save for at Big Box Stores it's probably razor-thin. As such, you kill a lot of your major (as well as minor) retailer loyalty if they have 40 cards on the shelf that they paid, say, $20 for and now they lowered the MSRP to $17.50. It's not much, but the major retailers won't like it and it puts a dent on the small mom-and-pops since they can either not carry the cards thereafter (losing further sales down the road) or simply buy the minimum # of cards possible and pray for no price fluxes.
(3) When the price for points starts to fluctuate with the dollar then you have a situation where smarter gamers are just going to wait several months or, potentially, years to pick up those XBLA titles since they are always offered. Why buy points now if you can wait for them to drop a few bucks apiece?
I apologize for playing Devil's Advocate for a moment, but I thought it is an interesting situation to observe. Also, if you really want to go for impact you should start a simple (yet professional-looking) website with the problem and potential solution written out clearly and patiently. Make the approach more towards a letter-writing campaign (yes, actual letters) rather than e-mails since the former catch far more attention due to the amount of work involved than the latter. Provide several well-written form letters people could use if they do not feel like writting out their own personal letters. Toss in the address info the letters should go to and give it a go.
Even still it doesn't guarantee a victory of any sort, but it will get more heads to turn than an e-mail frenzy. Remember, in most cases the old methods of attention-grabbing still work best.
