I don't completely understand the premise of this thread. :p
But! If there was a chemistry/attraction system in the game I'd probably play around with dating and relationships more. It's was really fun in TS1, TS2 and in TS3. I used to play around with romance in TS4's beginning but it got old a bit fast.
In TS4 it's wayyy too easy. I have had sims met and marry all in the same day in TS4. You couldn't do that in TS1 and TS2 due to the long term relationship bar. It's was actually impossible to do that, unless you did a relationship spell or used a potion. But even without that in TS3 I would find it harder than what it is on TS4. Simply because in TS4 anything goes. In past games hugging someone with a low relashionship status would result refusal. Even certain interactions that weren't on par with the other sim's traits would be refused. That doesn't happen in TS4, evil sims love being hugged to pieces it just doesn't make any sense. And since doing flirty interactions quickly results in both sims getting very flirty very fast, it's harder to get sims to refuse advances because of bad emotions rather than the opposite.
But the fact that it was hard in past games made it all much more challenging and enjoyable. Sims also used to have wishes to get a partner, or get married or have kids, especially family oriented sims/with the family aspiration, which helped with the narrative of doing those things, as I always liked doing what my sim wants. But in this game those whims don't exist.
