I don't know of a single person that has sold cows or got out of the cattle business because of external, quasi-political influences like "bad press", foreign imports, etc.
As DLD and some others have said, drought is the dominant short-term reason and I don't think any of the other reasons come close. I remember the Dakotas being hammered several years ago, the midwest last year, and those of us in Tex/Ok for much of the past three years. Personally, we are hanging on to our numbers by a thread.
That being said, state water laws are not to blame. I understand what is going on in California right now, but to think that agriculture is the only loser in time of drought is just incorrect and takes our focus off actually fixing issues and becoming more efficient. In almost every part of the country, agriculture is the biggest water consumer by a long shot - as it should be. But when you just don't have enough water - nobody gets everything they want. Landscaping businesses in our area have shut down much quicker than cattle ranchers or farmers. Don't fool yourselves into thinking the urban Californian water users aren't more highly regulated than ag. They are everywhere - farmers/ranchers just don't hear about it and don't care. The reality is we grow lots of crops in lots of places they were never naturally meant to grow. For example, Arizona and California used to grow more cotton that almost all of the southern states. I think that has changed, but really?????? Cheap water has let us do stupid things for a long time. Drought brings those warts to light.
Changing demographics of cattle ranching is a long-term problem. One of the main contributors to lack of interest from young people is the fact their parents/grandparents are not only living longer, but are also healthier longer. Not that long ago, people were forced to turn over operations to their kids in their 60s as their health really started failing. A lof of folks in that generation now aren't willing to treat their kids the way they were treated. Add that in to the continued fragmentation of land, and it's just not a very good prospect right now. Emphasis on the right now part. My big question - and I'm really struggling on how to advise my sons - is will that always be the answer. When the current generation of land holders finally starts dying, will there then be a huge opportunity in ranching for kids that are now teenagers? Frankly - the opportunity doesn't really exist for those of us in our 30s and 40s right now - but maybe its just skipping a couple of generations. Will that be the case ten years from now? I really wonder what the demand for land will be?
Kind of the same thing we are seeing on "trades" versus college education. For many young rural men, I think there is a whole lot more opportunity in traditional construction trades (welding, electricians, etc) than there is in any of the non STEM degree programs in college.
I think its worth thinking about on how we advise your kids as they are evaluating career paths.