What happened here was atypical for Wikipedia "deletionism" debates.
Normally, when you read a story like this, someone created an article and someone else petitioned to have it deleted (with an "AfD") and there's a whole debate log you can read, and you could try to assess people's biases from the comments they left in the AfD.
Here, though, no article was ever created (prior to 2018, when Strickland was awarded her Nobel). Instead, a beginner editor wrote a draft of an article through the "Articles for Creation" ("AfC") process. AfC drafts are, apparently, reviewed by admins before being promoted to the "mainspace" of real articles. You can read the draft here:
https://en.wikipedia.org/w/index.php?oldid=842614385
This is a stub article --- merely the beginning of a real article. And that's fine; it's how lots of good articles start out. But it's easy to see how an admin churning through AfC stub drafts might not have clearly understood the notability of the subject. The article links mostly to the professor's own research group. There are hundreds of thousands of academics whose position in the encyclopedia could also be established with links to their research groups!
What I think is probably more important here though is that the original article, the one we talk about as being "deleted", was created with a special process where the author asked for permission to have it added. That's not how Wikipedia ordinarily works; you have to opt in to the permissions process. The author could just as easily have simply created a Strickland article in the mainspace, and the process that deleted it would have been more formal, would have included appeals, and there'd be a log of the reasoning. It likely would have survived. The author of the draft essentially asked for that not to happen, by using the AfC process.
It seems important to add here: had it been an actual article, and had it been deleted through a speedy deletion or a full-blown AfD process, it would be more difficult to get a Strickland article onto WP in the future (not "difficult", just "more difficult"). But there wasn't, so, in the entire span of time prior to Strickland's Nobel, anybody could have created a stub article for her and her work. From what I can tell, nobody did. That, to me, is the more telling phenomenon here, not the draft deletion.
Late edit
Complicating this story a lot, something I missed earlier: there was a tiny stub article on the site in 2014, but it was speedy-deleted for copyright infringement. (Thanks, commenters below!)