Julianna Soong made Data promise her that he wouldn't try again...
Okay, T'Preea. I watched "Inheritance" episode twice. Julianna didn't ask Data to make any promises, especially about making another android offspring. The episode revealed following information:
- There were 3 previous androids built before Lore
- Julianna treated each android like her own child
- Each android iteration had little chances of survival
- Julianna wanted to stop making more androids but Soong won and made Lore and Data
- Julianna was against Data's creation
- Julianna was guilt ridden over making Soong leave Data behind despite room in escape pod
- Julianna was afraid Data would be like Lore (evil)
- When asked, Julianna almost admitted she would never leave Data if he were her biological child
- If Data made an offspring, he would no longer be alone, which Troi knows how much this means to him
Based on the above information, Data should realize creating a stable offspring isn't as easy as shake-n-bake. It'll take time and, most likely, a number of tries.