Yeah it's appears similar to suicide bomber. Similar to how Beverley Crusher point out similarity to their plans to destroy the borg to be "similar" to genocide (they still proceed with the plan despite the superficial similarity to genocide).
However as the rest of the conference pointed out. There really is no analogous situation to other war when compared with the Borg.
As Riker pointed out there are no "innocent civilians" as all the Borgs are aggressors. There is no collateral damage. Every individual Borg that are part of the collective want to assimilate all sentient life and they do not negotiate at all.
Any analogy of comparison to suicide bombing or genocide doesn't really apply.
I don't think there really is a moral argument against wiping out the Borg (unless there is a way to liberate the collective by severing the link of all the individual borg was a reasonable alternative).
Regarding First Contact
I don't think there is anything wrong with killing all the Borg (considering I argued that point above). I think what Picard did there in the movie is completely logical and understandable and moral.
My point of arguing is not necessary that what Picard did was wrong or immoral or even inconsistent with his character. I think it was correct, in line with his established character
I just question whether it was consistent with the themes and message of the movie.
If you are going to have Lily criticise Picard for being hell bent for revenge, showing Picard mercy killing members of his crew (implication that Picard has hardened, mentally scarred), having Picard killing an assimilated Starfleet officer and having criticised for "enjoying it", have her criticise Picard for not even try to save any members. Then have Picard explicitly mentioned that when he was assimilated, the crew risk their lives to save him and hence he must risk his life to save Data.
The whole dilemma was whether Picard should blow up the ship to destroy the borg. However while I do think it is within Picard character that he only recently lost the Enterprise D and hence to lose the new ship to his worst enemy is unacceptable (I'm not criticising him for behaving out of character). I don't think that dilemma is directly related to Lily's criticism of Picard character. IF they wanted to go through that direction, they really should have flashbacks of Picard being distraught about losing the Enterprise D etc and build that up.
The logical conclusion to the character arc and criticism is then Picard recognising that his hatred for the Borg is corrupting his normal compassionate character and then recognising that all the Borg are just as much of a victim as himself as Locutus. The result is that instead of Picard killing all the borg, he finds a way to sever the collective and rescue all his assimilated colleague.
Regarding whether the Borg Queen can be "saved" or not, if Picard is forced to kill her to liberate the collective, I can live with that solution as well
I just feel that if they are going to have Picard kill all the Borg. They probably should cut out all the dialogue from Lily about him "not even trying to save Ensign Lynch"