completely ignored

Obviously that’s an exaggeration.

• https://www.bbc.co.uk/news/world-us-canada-57950149
• https://www.thespacereview.com/article/4227/1
• https://indianalawreview.com/2023/09/25/one-giant-leap-space-tourists-as-astronauts-an-analysis-of-the-outer-space-treaty-and-rescue-agreement-using-the-vienna-conventions-treaty-interpretation-method/
• https://www.reddit.com/r/spaceflight/comments/oo1jli/can_we_call_them_astrotourists_instead_of/

It says quite a lot

Does it? What if a thorough media analysis were to show that the level of discussion of this topic is roughly in proportion to the level of coverage of each mission?

Or that it is related to the extent to which these people are getting described as astronauts? For example, Shatner got a decent amount of coverage, but my guess is that fewer than half of the articles about his trip actually described him as an astronaut. E.g. NPR