I believe it is a humbler, more appropriate calendar for talking about human history. I use it on my personal site because I don't need to conform to societal standards on my own site (although I don't use arguably superior numbering systems like dozenal or base-60 because that would be far too confusing)
I feel that Gregorian makes it pointlessly difficult to talk about anything between 10k BC and 0BC, and warps intuitive understanding of some of the most important time periods in human history - for example, ancient Rome sounds ancient, but understanding that it existed 10,000 years into human society and we are only 20% later is helpful.
Personally, I think the ~0BC Mediterranean societies carried out some of the most important and interesting work of humanity, and I'd like to improve my feel for the course of history around and since those times.
I'll probably do a blog post soon with an interactive map and calendar from 0 HE to 12,020 HE that really showcases the true time in between important historical periods.