Prometheus' trailer did a great job of it but you're completely right, you can't please everyone. I'm not denying that. I know that full well. The Alien fanbase is such an eclectic collection of people brought to the series for all sorts of varying reasons.
And many people did like it which is great. But remember we're dedicated fans recording for other dedicated fans. If you look at our own reaction polls, you see a pretty steady flatline regarding people who loved it, were indifferent (most popular option being in the middle at good) and hated it. So in our corner it didn't work completely.
And "so what, it's just a trailer" is dismissive.