Sure, use an incident flashmeter, that works too. However, many people already have a DSLR but not a flashmeter; buying a flashmeter is expensive for a hobbyist. A DSLR works extremely well for metering, it's not rubbish and it gives perfect results if you do it properly. I have quite the collection of chromes to prove it.
Originally Posted by Poisson Du Jour
No one is forcing you do throw out your beloved flashmeter but just because a process is different from what you personally do doesn't make it wrong.