Q: How do I disable this so that some of my valued apps might run on El Capitan?

Here is a discussion with the steps:

https://apple.stackexchange.com/questions/208478/how-do-i-disable-system-integri ty-protection-sip-aka-rootless-on-os-x-10-11

However, you should first really consider why you would want to do this.  If SIP is breaking an application then it's for good reason.  It typically means that the developer of the application was not following best practices and was allowing the application to store or modify files in system directories that should not be modified by any secure and well-behaved application.

Maybe you can say more,why disable SIP to run software?

Disabling SIP is easy enough from Recovery:

csrutil disable

However I would suggest re-enabling once you accomplish your task:

csrutil enable

What are the names of these valued apps that the developers have been too lazy to update for SIP?