I'm one of the archaeologists on the forum. This kind of topic is one that is often discussed.
Bluntly, people wreck sites. People trash sites, they peck away at them until they are utterly deformed and debased. They have this 'need' to make their mark on sites, to leave something of themselves, or to take away a 'remembrance' a 'souvenir', but in doing so they slowly destroy the very thing they came to admire.
Foot traffic alone destroys the ground, wears away the structures stability and weathering ability.
People clambering over stones destroy fine detail, wear away carvings, and the damage is cumulative.
So, paying for access, creates a 'value' to the site, and that value pays for security, for maintenance, for repair, and a hopefully truthful and unbiased information based explanation of what we know.
The site as it is now, is not the site that it's builders conceived or built. It is simply the wreckage of that site, and it's place in pre history.
Adherents of modern religious practices layered onto the bones of past often do not accept that their interpretation is just that.
We have no way to communicate with the people of the past. We can experience Stonehenge through our modern eyes and senses, but it is not as it was through their eyes, their senses, their cultural affinity or their religious rites and devotions.
Everyone has an opinion, but too often they cherrypick the facts to make it fit, instead of making the interpretation fit the facts.
So, if people really want a site where they can practice their devotions, feel anchored to the past and the future, to be part of and aware of the turning of the year, the Earth the Moon the Sun, then go and build that.
Create something to be now, and to leave for the future to wonder about.
Stonehenge is part of the cultural history of us all, not just those who claim it as a religious centre.
M....who did celebrate the Solstice