In terms of users they obviously are the market leader. I use Outlook.com personally and consider it to be overall better than Gmail. I'd gladly debate this if you'd like.
Never the less, my original point was that all of these Gmail strengths that you think are very important are obviously not very important to people using Yahoo or their ISP webmail. The idea that everyone uses Gmail and any competitor must compete feature-by-feature is just incorrect.
This sounds an awful lot like telling your customers they're wrong. And if you find yourself doing that, it's usually because you don't understand what your customer wants.
Never the less, my original point was that all of these Gmail strengths that you think are very important are obviously not very important to people using Yahoo or their ISP webmail. The idea that everyone uses Gmail and any competitor must compete feature-by-feature is just incorrect.