It's a new franchise, it's more important to be know for as much people as possible in order to break a niche. With only 1 million sold I think it will hardly have an anticipated sequel
It's better to have a consistent fanbase than a flash in the pan moment all of Nintendo's franchises started this way and built themselves up over time through the brand's reputation for quality. The 1m who bought it with out issue will likely stick with with it much like the Metroid fanbase have with their series and Xenoblade has shown the growth not only happens with out what you suggest but it's more organic growth that is consistent in the long run, dropping a game to bargain bin prices also doesn't guarantee sales look at the original Bayonetta when it was on PS3 and 360 it only manage 2m total at those prices the second game with less sales made more money that it.
This is why it's best they stick to their approach because for all you know you can drop prices and it'll only sell to the same people who would have bought it anyway.