What I never understood about Nemesis was why, when B4 was discovered, they all acted so surprised that there was another android like Data. Did they all just have their memories wiped in regards to Lore?
I've never understood this complaint about B4. Lore is not an option, his remains are a known quantity. The crew know that there were more than just Data and Lore created, have discovered "unknown" Soong-type androids in the past...so their reaction seems pretty legit to me. Mild curiosity over having found another one, and Picard makes the comment about Soong having a penchant for whimsical names. What exactly is the problem?
Agreed, I've never understood this criticism either. "The crew act like they've never seen another Soong android before" is a commonly heard nitpick of Nemesis, but it just ain't true. Oh sure, they don't mention Lore by name... but as you correctly say, they do
acknowledge the reality of there being other Soong androids, and they've got no reason to assume its Lore because, again like you say, they've probably got what's left of him safely locked up in a Starfleet facility. And they've got no real reason to distrust another Soong android just
because Lore went a bit wrong...
In fact, the movie does
have a tacit acknowledgement of Lore, without actually mentioning him by name. When B4 is shown to have betrayed the Enterprise crew (albeit unknowingly, as a pawn of Shinzon), Data's reaction is almost
one of anger, as he declares "You are dangerous!" and shuts B4 down. His reaction makes perfect sense because he's disappointed in himself for taking B4 on trust and for putting the lives of his friends in danger, the unspoken line being that he's thinking he should
have been more wary of B4 after all that business with Lore.