You might be right.

With the "&limit" parameter he can change how many items he receives per HTTP request. This has nothing to do with a limit on how many HTTP requests he can make per TCP connection (pipelining). Maybe that is the "100" he is complaining about, i.e., 100 items per HTTP request.

However you failed to answer my question: Is he making 100 TCP connections to make 100 HTTP requests?

Does the Reddit server set a limit on how many HTTP requests he can make per connection? (100 is a common limit for web servers)

Sometimes the server admins may set a limit of 1 HTTP request per TCP connection. This prevents users from pipelining outside the browser, e.g., with libcurl or some other method.