I'm not entirely sure I've understood your objection properly, but I'll try to address your questions.
Yeah it's expected that I'll be put in unusual situations, no I don't expect authors to anticipate each trauma I could possibly have, but surely the very obvious ones can be covered.
Should art immitate life or be safe? Neither and both, there's plenty of room in this world for the most gritty horror movie and for Blue's Clues.
How could I have known it was the outcome? The trigger warning was as specific as it needed to be - "TW: Suicide" is plenty.
ETA: The general vibe I'm getting here is you're asking, "where do you draw the line?", as if this were a slippery slope. The answer is, it's a matter of taste and judgement. It's not any less tractable then the question, when do you decide a work of art is done?
Naturally this opens up the observation that, if it's about judgment, one could decide to include no trigger warnings, like my friend did when presenting the game to me. And sure, I'm not saying that's invalid. More that its bad taste, and I've elaborated as to why I feel that way.