Actually that's not the case at all. Google Apps users use the "regular" Gmail as their daily email client day in and day out, and there are over 6 million of those users who pay for the right to use Gmail as their client. They're not casual users who receive 5 or 6 emails per day that are mostly promotional, they receive upwards of a hundred emails over the course of a day in running their businesses. If you look at the most popular email client in the world, Microsoft Outlook, it has tons of advanced features to satisfy power users. For Google designers to err on the side of casual users over advanced users was an error and I'm glad they were called out on it by their own staff.