Sony doesn't own UHD from what I understand, I don't think they owned BR for that much either. They certainly have shares in it, that being said, they may have less shares in UHD BR.
They don't seem committed to the standard, their latest offering: http://4k.com/news/sony-finally-ann...blu-ray-player-with-high-dynamic-range-16496/ isn't even being sold mass market.
It's pretty clear they are not committed to UHD disc format.
They probably have data that suggests it hasn't been beneficial for them, or they are banking on the world moving to streaming technologies and/or would rather promote streaming technologies of their own service where they would receive a greater return on investment.
Not sure how much weight the format war between HD-DVD and BD had on the BD in PS3 decision had. But there is no format war this time, I think, so Sony might not need to be flag bearer for UHD, like it might had to last time. Or it was just a bonehead move of them to actually push BD as hard that time.
Is there any public info, that says the BD push last time was a good decision for Sony, Sony Playstation?