Is simple. When you are near someone physically, and you look at them, you are either attracted or you aren’t.
Realizing this would make the process of dating much more efficient, in my opinion. Desperation and fearfulness of being alone causes people to look beyond what is empirically obvious – for things that can support their feelings for a person. This is not attraction. This is just ‘stuff’. If there is no basic attraction, you are using the person.
This isn’t inherently bad. I think there are many situations when two people use eachother symbiotically, and it’s part of life. The problem is when people in this scenario take more serious steps such as buying a house or having kids. With no basic attraction these dynamics are sure to fail.
Attraction isn’t all that’s required, however. All of the ‘stuff’ that follows, such as mannerisms, sex & personality, are crucial for the longevity of the relationship. However, I find that clashes in these areas are often usurped by the existance of solid attraction. For example, pulling samples from relationships I observe with people in their 20s, it seems like a lot will be sacrificed for the sake of attraction. In my opinion, it remains as the birthplace for all things relationship-related.
In my personal experience, I have forced a failing relationship that only really had attraction as a commonality. I have also tried miserably to win the heart of a strumpet who is simply not attracted to me. In the latter case, in times past, I have tried to justify the possible success rate of a hypothetical relationship with myself and said strumpet by suggesting that the ‘stuff’ alone could hold it together. I now realize that this is a farce. Stuff is stuff.