So Lal v1.0 was a success and a failure at the same time. Lal exceeded Data expectations:
- using contractions
- feeling fear
- feeling love
- turning Riker into a bumbling idiot at 10-Forward
Data failed with Lal v1.0 when her positronic brain couldnt handle the stress that StarFleet may take her away from her father.
Why didnt Data attempt another pass at making Lal v2.0. Afterall, Data is the last of his kind. I doubt there'll be more B-4s laying around the galaxy for Data to find conveniently before sacrificing himself for the greater good.
Already Data has a head start. Lal v1.0's memories are still in Data's head. He could've built another android and research and fix the problem. If Lal v2.0 failed, then try Lal v3.0, v4.0, etc. Even with success, make more androids, like Data's son, named Lol (pun intended... LOL!)
To stress my question again: Why did Data give up trying after the first attempt? Hello, Data! You fell off your positronic horse. So what? Get your narrow, artificial ass back up on that horse.