This problem is only so bad because of the disgusting quality of English cards.
The pros of Japanese cards have been stated over and over:
1. Higher quality- why aren't English cards of the same stock and quality? These Japanese cards are glossier, bend/scratch less easily, and are more resistant to dirt.
2. Better randomizaion- I don't know what happened with the PT batch, but the card printers are doing a HORRIBLE job with "randomizing". I've seen a general pattern of "type" boxes. For example, collectively I got 3 boxes of Platinum. I pulled 3 palkia G lvl X, and 3 Shaymin lvl X. No other level X. My holos and rares and other cards followed a similar type of pattern through the boxes. I have countless Infernapes and Blazikens, but zero Ampharos. All three boxes I opened were virtually identical. I've heard of many other people who get these Palkia/Shaymin type boxes, and there appear to also be some kind of bad lvl X box (with giratina/drapion). In any case, the randomization of English packs has just gotten really absurd. It's getting worse, as most collectors I talk to realize.
3. Better rarity levels- I don't know why, but it costs some 90 dollars to buy these pieces of cardboard so that only a fraction of the cards are even playable. I could opt to buy Japanese boxes, with higher level X counts and higher holo counts, because those are the PLAYABLE cards. It makes the HARD TO GET cards easier to get. Eliminating them from use furthers the burden on English cards fulfilling the same roles. I expect prices to further inflate.
4. Better for shuffling- The cards appear to be of a type and quality such that they shuffle better. Try it and deny this.
There are many benefits to Japanese cards from English cards. I think the real problem here is not of Japanese cards being used for gamesmanship, but the lack of quality in English cards. If English cards were better quality, all of this would be moot.
Remember the real root of the problem: English cards are inferior in economic, aesthetic, and tangible terms. They are of a worse randomization, worse rarity ratio, worse printing quality, etc. If English cards were better, no one would WANT to buy Japanese cards. No one would NEED to buy Japanese cards. Pokemon should be asking themselves why the community, especially the better players, are so displeased. Is it because there is some emotional attachment to Japanese cards, etc. Yeah, maybe a little bit, but I think it's more that we will be forced to buy inferior product at a higher price and to spend more money- while simultaneously having any current stock ruined, and not being allowed to play in a style and manner they have for years.
For States this year I was FORCED to use Japanese cards to PLAY in the events because English cards were simply too difficult to get/pull. Try getting 3 of the same playable level Xs from PT with any amount of luck and then consider the ease of trying this task in Japanese. I don't know how I'm going to do pull off the same feats next year, trying to provide enough cards to have everyone around me play Pokemon.
These are tough times, and POP has made them harder by forcing the community to buy their inferior product.