Why are some page properties disabled on AEM We Retail reference site
I am doing some search-engines related research on Adobe Experience Manager's reference site - We Retail.
I've realised that page properties on some pages (ex. http://server:port/sites.html/content/we-retail/us/en/products) are disabled like it is shown in this picture.

Tried on another clean instance, it is the same.
What could be a reason for this and where it can be enabled for editing again?
The interesting fact is that I can edit the same page properties in page -> page information -> edit template -> page information -> initial page properties This tells me that there might be some restriction in product-page template, but it has the same properties as content-page template.
I am logged in as administrator, so there should be no permission problems.
AEM 6.4.2v
