Bandai did the same with the Wonderswan devices, which competed against the Game Boy Color and Advance. The device was only released in Japan around '98 - '01.

And so now, if you want to use headphones with it (and you do; as not only do you get stereo instead of monaural sound; you get an extra channel of audio so you'll be missing certain sound effects in some games without them!), you get to buy one of these pricey ($60-80) adapters for it, plus shipping fees from Japan: http://www.ebay.com/itm/361198122142

Of course, if you really want to see the fun of removing standardized ports, look no further than the Gamecube's component cables, which sell for a cool $250+ today: http://www.ebay.com/itm/131939975870

So, yeah. I'm strongly in favor of industry standard ports, even if it adds a few pennies onto the cost or a few mm onto the device size.