I think it's likely that more people have seen works(videos) of those pornstars than works(papers) of those scientists. Also that more people remember names of those pornstars than names of those scientists. So I think pornstars are more famous. Whether that should translate to more Wikipedia notability I have no idea.

I have no knowledge of the actresses' area of expertise, yet I can fully enjoy their work. But without at least a MS (maybe a BS in some cases), I doubt I can fully appreciate the work of the professors.

Personally, I believe the work of the scientists of course deserve more recognition. But if you were going to go down that road, I'd start with trimming the wiki entries of pro-athletes or generic Hollywood celebrities. Their lives and contributions affect me even less than pornstars.

It's a question of why notability requirements are stricter on academics than pornstars. A fairly comprehensive list of pornstars will not be super huge, especially compared to academics, and will have fewer cranks trying to push a point of view through those articles. It comes down to a pragmatic point of view, not an actual argument that the least notable porn star on that list is more notable than the most notable scientist excluded from the list.

I personally say let them all in, but that battle has been fought and lost long ago.

Having just visited that page, it's unfortunate that the wholesome-looking young lady currently in rotation asking for donations appears at the top of it. Sometimes banner ads can really not suit the page content.