For such users, there is a way to hide that banner from appearing in the Mac App Store. Not only will you not see the banner, you will also protect yourself from accidentally downloading the update to your Mac. Note: this should remove the banner from the updates section in the app store. Apple might still show the banner on the homescreen of the store where you see some random new apps every day.
Hiding OS X El Capitan Update Banner in the Mac App Store
For this tas, you do not need a third-party app. All you need is the Mac App Store on your Mac, which you already have, and the toggling of an option here and there.
Click on Launchpad in your dock, search for and click on “App Store,” and it will launch.
When the App Store launches, click on “Updates” on the top to be taken to the updates section where the OS X El Capitan update resides. You will also see the updates for other apps in that section.
On the top of this screen is the large update banner that you want to get rid of. In order to do that, you need to right-click on the banner and select the one and only option that appears – “Hide Update.”
As soon as you click the option in the previous step, the banner will be gone immediately from your App Store, and you will see that large space being occupied by the things that actually matter to you for the time being.
If you ever get yourself ready for this latest version of the OS X, you can fire up the App Store, search for and click on “OS X El Capitan,” and install it on your machine. What you did above is just remove the banner from appearing in the App Store; you have not actually removed the whole update from your store.
Conclusion
If you are not yet ready for the latest OS X update and find its banner in the Mac App Store to be doing nothing but occupying the precious screen space, you can have it removed using the procedure described above.
