Nope. Sentimental scenes are most of the times utter crap. Scenes that makes you actually think and reflect usually leave you fairly cold while you watch the movie. I already mentioned the prime example, Kurosawa's "Seven Samurai". You see heroism and sacrifices in it but you do not shed one tear for anybody who dies.
I mean, gee, this is basic stuff. Cinema can work like classical drama but it does not have to ... and even classical drama does not necessarily "genuinely move" you. I'd be surprised if a reader or viewer of Hamlet really empathizes so deeply with the protagonist to actually care much about his death.
If you did not move your audience, it's usually not because you simply chose not to.
Again totally wrong. The best German movies are those of the so called Berlin school: little is happening, characters do not talk that much, the audience does not empathize much with them, the camera perspective is fairly neutral ... in short, these movies are fairly Brechtian. One of the best German auteurs has been Fassbinder and he worked also like this. And of course I don't have to mention New Wave directors like Godard, Truffaut or Rohmer. I also recently watched some fine Turkish moviemakers like Nuri Bilge Ceylan and Semih Kaplanoglu and they also work in such a "dry" fashion.
So yeah, this claim is utterly ridiculous and it illustrates how some folks are unconsciously impacted by implicit Hollywood standards. Nothing against Casablanca but it is not the only way to do good movies.
Back to Trek, I fail to see why Kirk's death is inferior to Spock's or George Kirk's just because the audience does not cry. The scenes makes a point, Kirk dies basically alone in the middle of nowhere. Nobody will visit his grave as his Starfleet family is long gone and in the Nexus he has chosen against starting a normal family during retirement.
I prefer such quiet notes over blunt emotional manipulation anyday.