I happen to experience what could be described as 'spirituality' at these places... a feeling that somehow the world does mean something. Not in a concrete, definable, measurable sense of course, but within that bizarre, (currently) unfathomable world of introspection. Just electrical pulses. But guess the point is this is the medium we've always used, so for me these sites are still relevant, doing their job.
And occasionally sites have brought anger and disappointment, when they've been badly abused by people.
Purely my own opinion, but I wouldn't probably use the word "sacred" to describe these places, as that carries some kind of "higher being"/religious connotations, in my mind anyway. Any religion practiced at them now is essentially made-up Victorian romanticism, no matter what the druids might tell you. But spiritual? For sure. The high, remote places are invariably a salve and a tonic. Just not when there's a coach trip arriving.