I absolutely agree. If you have the expertise to build and maintain your own site and you have the time to do so, then by all means that's the way to go. Especially if you already pay for your own domain name. But I think the target is for people that are going to opt for convenience over customization/functionality.
I think it's important for people to weigh their options. And decide if any of the features I've listed above are of any value to them. And don't forget that there is almost no setup for these features. You don't have to build anything and configuration is a matter of a few simple steps.
Again, as you stated above, if all you need is an email account then there's no reason to spend $99 bucks for a bunch of features that you won't use.
Personally, I'm surprised at how many of these features I've actually ended up using.