While there might be some niche use cases, this would open a horrible can of worms. Why not include their basicicons as well? That would potentially be way more useful. What about donator status to estimate energy related metrics? Heck, let's add the entire output of user/profile to save making extra calls.

Do you see how this could get out of hand? Could you provide a reasonable, commonly used case for when you need the user's exact life at least?

That would just increase response times and server strain for the majority of times when you don't need all that extra data.

The case I'm imagining is when you're warring and want to see opponents life when you're selecting targets.  Most of the other stuff in the user response doesn't change very often, so occasional user requests will pull those values.  It's life, last_action and status that change more frequently that would trigger more pulls.

For all I know, the api controller already has the data from the DB when looking up the other bits (E.g. last_action and status), and so including it may not materially increase the server load, other than by an extra few bytes in the response.  And there's all sorts of info in each response that may not be used in the majority of cases (e.g. what % of API users actually care about married status, or friend/enemy/karma counts?  If you're going to take that approach, you might as well include request flags for what response components you want and which you don't.  But that would unnecessarily complicate the code for not much of a win.  I'm curious how many API consumers end up polling the user API more frequently than they would in order to get that info...it might actually reduce some some server strain by eliminating a bunch of unnecessary user queries.

It makes reasonable sense for friend/enemy/karma counts to be accessed with a user API call since that information is on the profile page. However, you can't see life on the faction page which is probably why you can't get it directly with a faction API call. Also I don't know your exact use case but I'd imagine you could probably filter out members by last_action or status and then get the life of those players afterwards.