mainly because of Jed and his girlfriend. They are not trustworthy people, and Stellar is probably the only company that "claims" to be a charity and holds more currency in private holding ( not trust, not foundation etc ) of the board.
And Jed's is known to cheat ( check his initial ripple sister firm formation to siphon funds to his girlfriend, his fued with ripple, also trying to dump xrp ) - SO all in all Very shady character. I know for sure in banking and industry no one wants to deal with him. In fact wells Fargo and other banks warned Chris Larsen to stay away from him and if not, they said they wont even deal with them.
Also i hope you remember It was Jed's laptop from where Mt Gox Keys were stolen apparently "accidentally"
I want to ask you on contrary ... Why would you go long ?
Ripple and Stellar are polar opposites when it comes to integrity and dignity.
If you say Stellar is ripples little brother, then perhaps on of those brothers which goes rotten and end up in prison.
I know people buy and sell on profits, but Long ? actually, why would anyone go long on anything run by a fraudster like Jed is beyond me ?