Ah, yes, that IS the big difference. And I'm having a hard time thinking of any episode of any Star Trek I have watched (
never seen much of Deep Space Nine or Enterprise) that didn't wisely bring the focus back (if it ever momentarily departed) to the main cast of characters, where the audience's emotional connection lies.
For the vast majority of viewers, the only possible emotional connection with the destruciton of Vulcan was the death of Amanda, the solitary known character. Even this was iffy, as I don't think we'd made any emotional connection with her new incarnation. It's not enough to just don an Amanda mask and, viola, you're Amanda.
The big success of the new Star Trek, imo, was establishing an emotional connection with new Spock and new Kirk, et al. If they'd have ...
Spoiler:
killed Spock in the first five minutes, I really wouldn't have cared either ... because Quinto had not yet established himself to me as Spock. Similarly, killing off Sulu would have little effect, because ... to date, actually, that actor has not really established himself as Hikaru Sulu.
So, no, not at all the same as killing Wash, which was a fantastic move. But, in any event, Farscape is a little grittier than Star Trek. Still, brave and effective ... but perhaps because it had never been done. And why am I spoiler tagging something from a 5-year-old movie?