Yea but sometimes retaining apps in memory can have a negative effect on battery life. It's usually better to have the android lifecycle kill the app as needed. When apps are restarted they're restarted with a stored bundle of data and when you have a fast CPU that means those apps come back incredibly quickly. Of course it all depends on how well the app is made, but some apps have memory leaks or are just badly coded (Facebook etc) so having those types of programs in memory indefinitely with a ton of RAM will harm the performance of your device.
That said, I run a lot of memory intensive apps on my nexus 7 & have never had any want or need for more RAM