The audience should not have made assumptions about the film and the direction it was going, then. That is, again, their fault and no one elses. It's not Cloverfield's, nor any films, responsibility to cater to their predefined notions of what 'should' happen based on their familiarity with the genre (again I say, I doubt anyone who was shocked by how the film ended is actually very knowledgeable in the genre, or the subgenre, that is, the subjective camera type film, this type of ending IS conventional for that type of film). It's not bitterness and it's not uncalled for, I'm placing blame where it should be put -- on those who lazily thought one thing for no reason other than "well, that's how it usually happens. You say it's a strength of Cloverfield and not a fault of the audience, I say it's both.
No, it was not an ending of sorts, it was an absolute ending. The story about these characters was finished, there was nothing more that could logically be told without breaking the immersion (key word, that is the whole point for the film existing, storytelling was second to immersion). Really, the way the film ended was the logical conclusion. Considering the fact that it was created to try and be realistic, that's what would probably happen in real life - people die during disasters.
Again, if people actually expect
Spoiler:just because that's their goal, then that's just the audience being lazy. It's a completely illogical assumption because it's just that, an assumption based on predetermined notions that the film never intended or hinted at. A character having a goal doesn't imply that they will inherently achieve that goal; there are plenty of films where the characters totally fail in what they are trying to achieve. This is not new, this is in many conventional films and I really don't think this is even why people don't like the ending. I'd still love for someone who actually had a problem with the ending to come and tell me specifically what else they wanted the ending to do, or what problems they actually had with it. It seems you're just taking your best guess as to what the people didn't like about it, I've not actually heard anyone say "I didn't like that
the protagonists to escape
Spoiler:." I've not really heard any specifics, I've heard vague and ultimately invalid opinions that are not backed up or defended in any way, like "The ending was stupid" "Why?" "CUZ IT SUCKED".
the characters died