Seriously though, is there any reason for me to invest in Dash, given the evidence? (genuine question)
Because it might go up in value?
If you are looking for long term success, no, there is not really a basis to expect that, and the disreputable background documented here only makes that less likely.
If you are looking for short term swings, sure, go for it if your research supports it and you can afford the risk.
Be careful if you are playing big though. The liquidity in Dash is quite poor, both relative to the market cap and in absolute terms. Most likely because the vast majority of the coin supply doesn't ever hit the market, it is HODLed by instaminers and early adopters who have it locked up in masternodes.
For small-size trading where you try to time the market and don't need to worry much about liquidity, it can be as good as anything else.