Re: Spocks line *Major Major Spoilers*
The laughable cornball moment was when Kirk (Shatner) got to emote and yelled, "Khaaaaaaaaan," in TWOK. It was cringe-inducing when I saw it for the first time in the theater, and it still is, today.
In the context of STID, here's Spock, who we know is still wondering how to deal with the emotions that churn just below his surface. Here's Spock, who has lost six billion of his fellow Vulcans, his mom, and now Kirk. Sure, they'd been together only a year, but Spock Prime had told him that in his universe, they went on to have a long friendship and accomplished great and unique things. It was important that they were together. Now, that chance has been taken away from him, too.
Should Spock be pissed? Agonized? Enraged? This is the last straw. At least this time, "Khaaaaaaaaaan" has some meaning and is a justifiable primal scream.
If Trek fans laugh at it, I'd say it's because we always took it as an over-the-top laugh-line from TWOK. The risk the writers took this time was an attempt to finally give the line real gravitas. Too bad it seems to have failed for a lot of fans.