Imagine you have a table of results and each one is taking time to render. You add this for each row, but you only test it locally with a few rows. In production, maybe that table has hundreds of rows.
You've just DOSed your server.
Before using a library blindly 1. Ask yourself which problem you want to solve 2. Educate yourself 3. Does the library solve you problem 4. Use with caution 5. Learn from you mistakes :D
I still hold that sparing use is important.
The overhead for steps before your controller action method can often be a significant portion of the overall response time.
Under low load, it could make it faster for one user.
Under higher load, each initial page request will be more expensive and therefore will result in exhausted resources sooner.
The limit applies only to persistent connections.