"using the government to seize private property"
Hey, I hear you. Property rights are important.
The thing is, not all property rights are equal. Some are more established than others.
Owning land and owning our own tangible possessions are some of the most firmly established rights. Even in these cases there are carve-outs for public good (taxes, eminent domain) but I'm right there with you that we should seek to preserve these property rights above all else.
But there are other property rights which are much less well established, and which change over time. Copyright, for example, is a relatively new property right and it has changed, expanded, significantly since its inception. When we talk about reducing the scope of copyright, are we talking about seizing private property? Well, maybe, but only in the same sense that extending copyright is seizing public property and making it private.
Water rights in human history are older than copyright, but the particular structure of western water rights in California is newer and less well-established. In fact, the basic structure of water rights is very different in the western US than in the eastern, and this difference is a major source of our water troubles. This didn't matter for a long time, but now it matters a lot.
Talking about correcting these types of incongruities inherent in the way we structure ownership is substantially different from the banal picture you paint of seizing tangible, real private property.