As described in the protected-questions privileges:
Questions should be protected when they are garnering lots of views and newbies are adding "me too!", "thanks!" and possibly even spam non-answers.
(emphasis mine, and yes, I do realize it is the first part of an 'and' clause.)
Any question at least a day old can be protected and unprotected by users that have the privilege.
This means that as the question sits on hot network questions and is getting all those views and poor answers that don't fit with the norms of the community, all the 15k users can do is sit there and wait for it to age to 24h or flag it for a moderator to protect it.
Meanwhile, new users are adding poor answers, answers that should be comments, getting down voted and having a less than ideal time. One can certainly debate if it is a worse experience to be given a "you must have 10 reputation on this site" message or find that your 101 rep is now 95 because of some down votes - but that isn't the question here.
Yes, there is an auto protect, but that requires sufficient new users post and doesn't show any "think twice about this" type message at the top of the question before it happens (this is even useful for users with significantly more than 10 reputation on the site to be reminded to check existing answers to see if it is a duplicate answer or not). It also has a notable disadvantage that if answers from new users gain +2/−3 score (they've gained 14 rep) they are above the threshold for detecting the "three posts from new users (earned less than 10 rep)".
Related to this is the Allow users with 15k reputation to protect questions less than a day old, but with more than N answers which is based solely on answer count (and a good idea that really hasn't seen enough activity). This suggestion is to allow 15k users to protect solely based on number of views when the question is under 24h old.
Allow a question to be protected when it has gained N × [age in hours] views. N is per-site-configurable by elected moderators.
The value for N should probably be 75–100 for sites other than Stack Overflow as a ballpark value.