I believe this is an optimization. It works if you click Search when on the browse page. This reduces database queries. Imagine a site with 100k users. Before, going to the member browse would immediately do a query to the database to get all users and a count. That's a big query and getting bigger as the site grows. 

Stopping that initial query reduces load on the server. Users can click Search to get the count and that'll make the query happen at the time but at least it wouldn't be an automated query x the number of users and visitors going to the member browse page x the number of members in the database.