So trying to breed villagers was getting annoying and pissing me off
I know right? I'm playing on a different server where I had the same problem, I couldn't get my villagers to breed by letting them plant and harvest crops. They just wander around and not doing anything with the potatoes I threw at them. Sure, you can trade with them to make them 'willing' but that's not what I wanted, at least not yet.
Then it hit me: the mobGriefing gamerule. If set to false, which is the case on both my TWHL server and the one I play on, Creepers don't damage terrain and Enderman don't pickup blocks. I don't have a problem with Creepers blowing things up, but I do have a problem with Enderman taking random blocks and damaging the terrain like that. So that's why I have mobGriefing set to false. But guess what: setting the mobGriefing gamerule to false also stops farmer villagers from picking up, planting and harvesting crops! Well damn HELLS BLAZES FRICKER!
So, I can either:
1. Re-enable mobGriefing. Creepers and Enderman can damage terrain again, but farmer villagers can finally pickup, plant, harvest and share crops with other villagers to make them willing to breed.
2. Keep mobGriefing disabled. No Creeper and Enderman damage but farmer villagers will NOT pickup, plant, harvest and share crops with other villager. The only way to make them willing to breed is to trade with them.