Many people conflate explanation and justification. An explanation is a theory about why something happened or why we should do one thing rather than another. A justification is a story about why we are right, or probably right, to adopt one theory rather than another or one proposal for action rather than another. Explanations are good; justifications are at best a waste of time.
Explanations are good because they provide a target for criticism. If I say why I’m doing something somebody might come up with an argument against it that will change my mind. If I take an action for which I have some explanation and it all goes horribly wrong then I may be able to criticise my actions more easily if I can explain them. An explanation can also be looked upon as an encouragement to criticise an action or idea. An explicit statement of why it seems like a good idea invites people to pick apart the list of arguments I’ve given for my preference.
Justification does not encourage criticism. A justification supposedly shows that its conclusions are correct or probably correct, which means presumably that we probably shouldn’t bother criticising them. Justification also encourages people to waste time with endless fiddly details of a particular idea or course of action when often a cold hard critical look at the theory without the details will make it seem unpromising. I will give an example. I recently witnessed a philosophy discussion in which the participants were discussing knowledge by discussing the meaning of the phrase ‘to know.’ The participants were tying themselves in knots talking about justification and so on until somebody said that maybe there was something wrong with the way people usually think about knowledge and perhaps they should change their theories. The leader of the discussion then replied by saying, ‘Ah, but then we wouldn’t be discussing the meaning of the phrase “to know” in English.’ The discussion then waded into a mire of pointless precision and logic chopping. The person who spoke up against this way of proceeding was right. Just discussing the meaning of ‘to know’ in English means uncritically taking on board a load of ideas many of which may be completely wrong. This is a completely wrongheaded way to do epistemology, but the people involved in trying to justify the way people use ‘to know’ were too busy looking at the fine details to see this problem. As such they spend all their time working on a problem they could solve by spending two minutes with a dictionary instead of spending their time trying to solve interesting epistemological problems.