anyway Picard had just lost several members of his family and saved millions of inhabitants in the Viridian system - I think the loss of a mere starship was a pretty minor thing next to that.
No doubt. The reasons for the sacrifice of both the original Connie and the Ent-D are not in question; it's just the treatment of the reaction that's in criticism. In TSFS, we see a number of the primary bridge crew and series mainstays (Kirk, McCoy, Scotty, Sulu, Chekov) gazing up at the burning hulk of the very icon of the entire Star Trek franchise streaking across the sky.
'My God, Bones, what have I done?' 'What you had to do...' etc. The decision to sacrifice the Enterprise wasn't in question, but the emotional impact was addressed appropriately. In Generations, the Enterprise met its end in unavoidable fashion - though not by choice - it's just (arguably) regrettable that nobody was specifically portrayed at being emotionally affected by the affair. Picard's remark of there being 'plenty of letters left in the alphabet' accidentally comes across as dismissive of the Ent-D's service, as it were.
Part of this problem - if it is indeed a problem - is the difference in how Kirk and Picard were written as characters and what their relationship was with their respective commands (ships). Kirk was 'saved' on multiple occasions by his nautical-captain-reminiscent love of his vessel. In The Naked Time, he's brought to his senses when he recognizes his love for his ship ("I'll never lose you..."). In Elaan of Troyius, the magic, intoxicating tears of a mystical female seductress are nullified by his devotion to his command. To draw a parallel, the Best Star Trek Movie ever, 'Master and Commander', portrays Captain Jack Aubrey in the same light - he rises to criticism of his vessel (in respect to challenges of comparisons to a bigger, newer, more 'badass' ship) with a defense of the HMS Suprise: "She has a bluff bow, lovely lines. She's a fine seaboat: weatherly, stiff and fast … very fast, if she's well handled. No, she's not old; she's in her prime."
Kirk and Aubrey both identify with their respective commands as characters; in the tradition of naval captains, the ships are actors of the 'fairer sex' - and treated much the same as a chivalry-painted character would regard a lady: as a fairer sex, as a lofty ideal; as something to be cherished, idealized, and loved.
This is the disconnect between Kirk and Picard, and respectively, fans of either, and the their relative behavior (both the characters and fans) regarding the destruction of their ships: Picard, in TNG, never exhibited the 'love' for the Enterprise in the way Kirk or Jack Aubrey did. Picard's 'plenty of letters left in the alphabet' statement was supposed to reassure the viewers that the saga would continue with a new ship, but it comes across as hollow because nobody demonstrated a care for the Ent-D in the first place - it's more or less treated like a floating office complex. In that light, it feels like Picard is just being flippant about the whole affair by saying, 'who cares, they'll just create another ship with the same name'. Of course, another ship with the same name is not the same thing when considered by a Jack Aubrey or TOS Kirk type - these guys really view the ship as a personality, beyond a name or registration number.
I'm going to even drag The Final Frontier into this. I think Shatner (or/and the screenwriters) understood this quality, and that's why the newcomer - the 1701-A - had faults, difficulties, and shortcomings - they were trying to portray that she wasn't just an empty stand-in for the original ship (which would've degraded the memory of the original). She was a new, funky, borderline defective replacement (and they made that clear), and she had to earn her stripes, as it were.
Anyway, regarding the post I'm responding to - yes, the destruction of a mass of metal is worth it when you're saving a few lives, whether it be Picard's family or David Marcus or Spock's Mysterious Katra or whatever. The point of contention is the exhibited emotional response to the sacrifice made. The TOS movies paid respects to the Enterprise in terms of emotional quotient, due to the fact that TOS set up an emotional link between its characters and the ship from the start. TNG never set up the character of the Enterprise as anything other than the 'Federation's Flagship' and a generally cool place to be, and it's eulogy, as a result, was that there are 'plenty of more letters in the alphabet'. To force a scene in which the characters really grieved over the loss would have seemed out of place without the prior emotional setup that TOS enjoyed, anyway. It's really not a failure of the script of the movie Generations - it's a sort of general failure to ever establish the Enterprise as something more important than the 'floating office complex' it was, which robbed the sacrifice of the
sense of sacrifice. This lack of human-relatable sentiment stuff is part of a larger criticism I have about TNG, VOY, ENT, and the later movies, but I won't expound upon it here beyond this brief summary:
TOS had serious heart. TNG and the like was more clinical. Attempts to mirror TOS stuff in TNG-onwards stuff failed to carry the same weight, best exemplified by the fact that most plot elements/movie structure of 'Nemesis' were lifted directly from The Wrath of Khan, but failed to tap into its strengths, because, as is typical for TNG, they lifted the literal framework without capturing the heart.