Further confusing First Amendment jurisprudence

It was a couple of weeks ago, but it seems to me that in the case of City of Pleasant Grove, v. Summum, the Supreme Court acted very politically -- coming out with a decision that everybody wanted and that most people might say comports with common sense, or at least with what most cities would probably prefer, at the expense of anything resembling a coherent principle, further muddling First Amendment jurisprudence. The small city in Utah has all kinds of memorials in its city park -- historic and such -- including a Ten Commandments monument donated atround 1959 by a private group. A "new age" religion called Summum requested permission to erect a monument with its Seven Principles and the city turned them down.

The Supreme Court rejected Summum's argument that it was a matter of free speech to which it had a right in the "public forum" that was the city park. The court said it was the government's park and the government had the right to decide what could be put there permanently. But that seems to make the Ten Commandments monument "government speech." Could it then be removed on establishment grounds. I think the issue is far from settled, and the Supreme Court, which is supposed to provide guidance on confusing matters, has muddied the waters again.