All relationships need to have certain degrees of emotional closeness in order to work out. It can be a very bad sign about the status of your relationship if your partner is always trying to keep you at arm's length when it comes to emotional issues. While your partner doesn't have to talk to you about every issue they have, they still need to be able to open up about certain things.
The reason why it helps having a partner that is open emotionally is that that gives people a feeling of warmth and closeness. The more open a person is about their life, the more we can relate to them, which is one of the most important parts of having a relationship. If a person is not open to you, then some people may even feel like they are not even in a relationship in the first place.