Probably the only reason you are looking for is Dash Evolution, bringing Dash to the masses: https://www.dash.org/evolution/

As for other alts, there are lots of arguments either way, but it might be a good option to diversify and not keep all eggs in one basket.

The recent price rise of Dash has brought a lot of attention to the project, with the self funding Dash is in a great position to boost again as the release of Evolution gets closer.

Also noteworthy that most masternode owners did not sell during the price run, that tells me that people are not prepared to sell at these price levels. There is more to come later on.