Not really, he is just explaining that some veggies add a lot of taste for very little effort. People watch cooking programmes and think that you have to spend an hour cutting stuff up to make it worthwhile. Or that you have to spend a fortune on herbs to make it taste nice. When the reality is that just adding a single vegetable can do wonders for the taste. Onions are just the most versatile and one of the quickest to prep/cook.