The game is definitely not coming out this year first of, what footage have you seen of crackdown, state of decay or Forza? they are all coming out this year. It's quite common for MS games especially the trinity to not show much at all until closer to release.
The game is actively in development and is taking a community driven design, you can't market a game or aspects of it until you nail it down with your community. Rare's approach to testing is slow very piecemeal, everything is thought out methodically. The same way blizzard handles it, and in fact blizzards model has been used to describe the way in which they are going about it. Your only going to see what the community likes and Rare team is happy to sign off upon as final. It will start of slow but as we get further along in testing more and more will get added quicker and quicker up until a open beta and then release.
Your right there is a lot they are not showing, the skeletons are simply there to test spawn rate and accuracy for the rest of the game, mermaids have more of a purpose than a spawn point. They are set up in a specific way just like ferry of the damned for the alpha testing. In terms of quests there is a lot more variance, a lot of the world role specific quests are not implemented as roles are not yet implemented. Think of it as Rare has version 1.0 but it's unfinished, buggy, still in testing and final design hasn't been signed of on for even the alpha yet. Were as we are on version 0.1, rather than most testing we won't get jumps in 0.1's but rather 0.01's, as they finish of aspects of the game and polish to were their happy they implement them one piece at a time very slowly. As they get more confident in it's design as it's building on the already testing fundamentals and systems it will speed up just like in any game development timeline.
They multiply the size of the map and the variance multiple times in short gaps. For example the sword (dancing around this) would be finished in their version 1.0 but instead of implementing that whole system, they would implement just the fundamental aspect maybe leaving out the combos. They polish that then add another aspect, polish again and so forth until it would be fully implemented. This games alpha is more polished than the vast majority of release games, which is adding more time in development as it's being polished during development rather than towards the end. But you would find out a lot more to what Rare's doing with the game if you read over a lot of the posts in the insider forums. It's dangerous for Rare to talk about elements of the game to even insiders until there finished let alone the wider public or to market them.
But I agree if the way the game has been shown at the last two E3's is the way they intend to market it then they are royally fucked. Those showing's were awful, I don't know why they don't just at E3 do a 10 minute video quickly cutting between the different aspects and systems of the game. A fallout 4 style deep dive would be great or even just post 2-3 hours of raw gameplay going through the daily loop and a few teasers for the other activities.
