Speaking from my own experience...I think in general most psychics follow along with our intentions for getting a reading - unless they are tapped into something that goes beyond that and can give guidance from a higher perspective. They are going to answer what you are asking, not just the explicit words but the underlying intentions of your question. That includes wanting a reason to excuse someone's behavior, or understand it better. And to some extent I think they are channeling the literal excuses that person might give if I was hearing it from them.
I have found that on one day, if I was feeling sad and wanting to understand things, a reader might give me all kinds of reasons and excuses for why the person acted the way they did. Then on another day, if I was feeling more fed up with it, that same reader would be saying you can do better than this, he's immature, etc. I've also noticed my feelings on a given day would influence my choice of reader, even someone I hadn't read with before, I would just know whether they are going to be positive or negative about the situation and choose accordingly.
It seems like if someone loves you they would just be there for you and do right by you and not do anything to hurt you. But I think that's the fairytale version of things. Life is way more complicated than that. People have lots of things going on in their lives besides wanting to be with someone romantically. Job, health, money, children, aging parents, property, and so on. Then there are emotional issues, childhood traumas, baggage from past relationships. It takes a lot of effort to balance those things and it doesn't necessarily get easier as you get older.
These are all legitimate reasons why someone might not be there the way we want them to. They only become excuses when they are leading us on, not living up to their word and making false promises. Now that's what I think most readers are really exceptional at...leading us on with false hopes that we are going to have a fairytale with the person.
The problem is...again in my experience...if you get a lot of readings it can get hard to tell the difference between whether that person is leading you on, vs. the reader(s) being the ones to do it. The lines get blurred and you start expecting things of the person because the reader said it would happen, NOT because they said it themselves. Then the reader gives the excuses because the prediction did not happen.
It's up to each of us if we love someone enough or want to be with them enough to stand by them while they try to figure things out. The important thing in my mind is that the effort should be there. Not just intentions or wanting to, but having some real follow through. If they are not making an effort, if they are flaking out, then it's too one sided. They have to show me some real character and fortitude.