That is true... but, depending on the user, the restrictions may not be well-understood and could cause frustrations. Or, they simply may not make sense... for example, I can easily use my admin privileges dozens or even hundreds of times per day, so using a non-admin account is a non-starter for me.
But if you're able and willing to use a non-admin account day-to-day, or manage someone's computer who you think should not have admin privileges, I'm not telling you that's wrong. I don't believe there's a right or wrong answer here. My primary point is that it shouldn't be done with the expectation of protecting the system against malware, which seems to be the reason the vast majority of people give for using a non-admin account.
