You have to understand that most of the time (pretty much 99% of the time at this point, really), when the original Japanese voice-acting is removed from a game during localization, it's done out of necessity, NOT by choice. NO publisher is going to remove the original voice track if there exists an option to keep it -- there'd be no reason to, after all! But I speak from personal experience when I tell you that there are many, many times where publishers aren't given any choice in the matter whatsoever. Technical limitations and storage space aren't the only factors, either -- there's also that dreaded specter known as LICENSING. Sadly, everyone who's ever spoken a line of dialogue or sung a phrase of music in a video game signed a contract of some sort... and some of those contracts, ESPECIALLY in Japan, can be pretty draconian when you get down to the fine print. It's not at all uncommon for a Japanese voice-actor to record his/her voice for a game under the stipulation that it ONLY be used within the country of Japan, making it ILLEGAL to use those lines anywhere else in the world.
I'm not able to comment as to whether or not this is the reason we've removed Japanese voice tracks from some of our past titles, but I can give a relatively well-known example from the world of anime: Kodocha. When that show was brought to the U.S. by The Right Stuf, there were major licensing problems associated with the first opening theme, "19 O'Clock News" by the band Tokio. Not only was that song originally used as the opening theme for episodes 1-51 of the show, but Tokio's lead singer Mamo made a cameo appearance in episode 1 as himself, exchanging a few lines of dialogue with the series' main character Sana. And when the show was brought over to North America, absolutely NONE of that could be used due to licensing issues. Not only did Right Stuf have to substitute the second opening theme (originally used in episodes 52-102 of the anime) in place of the first, but they had to bleep out all of Mamo's lines from the Japanese language track on the DVD, and I think they even had to bleep out Mamo's NAME when Sana spoke it!
Now, that's a pretty extreme example, but it just goes to show you that Japanese contract law can be a HUGE problem, oftentimes leaving publishers with only three choices: release the game with dubbed voices, release the game with NO voices (bearing in mind that most games featuring English voice-acting also have an option to TURN OFF the voice-acting, so there's no reason dubbed voices are any worse than no voices)... or don't release the game at all.
And while I do understand your passion for playing things in their original language, I would urge you not to avoid supporting games simply because their language tracks have been dubbed. Remember, when you pay for a game, you're compensating the publisher for all the work they did to translate it, edit it, test it, master it, produce it, etc. We do a tremendous amount of work to make sure these games are playable and enjoyable in our own language, and it's extremely disheartening to hear that anyone would choose NOT to support us, even if it's a game they really want to play, simply because we were forced to dub the voice track into English. Especially since, quite honestly, I think most publishers would prefer to leave EVERY game in its original Japanese -- dubbing a game's voices is a time-consuming and costly process, and electing not to dub something invariably makes it take less time to release AND cost less money. And what publisher WOULDN'T want that?!
So yeah... bottom line, if you're going to "vote with your wallet," as it were, please make sure you know what you're voting FOR. By not supporting games that publishers had no choice but to dub, you're not sending the message that you want fewer dubs... you're sending the message that you want fewer games of that type released in English, period. And I'm pretty sure that's NOT the message you're trying to send.
-Tom