Going to join the choir here.
The DS is dead now - it's no longer being produced, and the same goes for new games for it. That's just how it is, and with options like the 3DS around as well it's not that un-affordable an option when you have 6 months. Family saying no is one thing, but then again, if you use your own money...
And at the time, it was actually surprising that they put BW on the regular DS. It seemed that it may have been better waiting for the 3DS, but that's what they went with (and sales turned out well anyway, unsurprisingly). B2W2 was one of the last games to come out for the DS iirc, and that was a sure sign that the next game would be 3DS. With X&Y being on the 3DS... really a given that any other games following would be too.