I do not think talking about "balance" can be about right/wrong or other negative dichotomies. You are never wrong for feeling what you feel. Feelings just are. You are never wrong for expressing how you feel. Likewise, T is not good/bad (another of those negative dichotomies :-) for working to help you not "throw out the mother with the bath water" :-)

Your parents were not just "did the best they could" nor were they "their best never good enough". You are learning to stand up in a boat without upsetting it and that takes some practice! What I do to help myself when I am in the predicament of being one way or the other in my perception and/or it is at odds with another I'm talking with is to back off and look at the whole or to remember that I am looking at a whole when looking at an individual piece might be better.

In what discreet experience you and they had together were they not good enough? Look at that instance you are thinking of rather than "all" of your childhood/upbringing? It might be possible to get a different perspective of an actual situation where it is not possible to for a "whole" childhood? Pull out an example that will "prove" your case with your T and discuss that example and you can learn more than just feeling bad alone that their best was good enough or not for you and wishing T were "on your side". Help your T get on the same page as you are currently on rather than lament she is on another at the moment. When I have not been able to do that, I sigh and try to go over to whatever page my T is on :-) and think how much I'm learning about other people's perspectives and adjusting to being in harness with others. T has been doing what T has been doing with clients for a long time and what I have been doing with myself and others, I don't think works (why I see T) so, it behooves me to at least try to do things T's way, even if it doesn't "feel" right to me; technically I could be the problem

What would you have done in your parent(s) case in that specific situation, being them instead of yourself? What other things did they have going on that you could not comprehend because you were not old/experienced enough in life, etc. and how can understanding their point of view help you now? It is very hard work being who you are now and remembering/being who you were then and trying to adjust back and forth to what you remember/feel/know about about your parents and being an adult in both situations too.

Think about your title of this thread? Neither of the choices (being angry or seeing "it" from their point of view) does anything for you? Anger is just a feeling telling you something needs to be done, something has been taken from you you want and you have to figure out how to get it back or adjust to doing without, figure out if it is/was yours or is/was taken, etc. And, seeing things from another's point of view is all well and good. . .for them, but how about you? How can it be made to help you. There's "action"/work that needs to be done beyond either of these choices.