WHY DOES IT MATTER?
Think of Learning Objectives as the bones of your course. Without bones, it's hard to support anything else. Learning Objectives answer the question "What will learners be able to do after the learning that they can't do now?" Pretty critical question. Said another way, how will everyone be able to measure this improvement? In the back of your mind, you might be thinking that if you leave it vague and open, you can fill in the real learning objective later when you figure it out. Bad idea. Vague and Open means everyone else can change the learning as well.
HOW DO YOU DO IT?
Here are a couple of resources for righting good Learning Objectives:
A snippet from my book Project Management for Trainers (Second Edition in 2Q this year!)
A fabulously provocative view of objectives at Thiagi's site
WHAT ELSE SHOULD I THINK ABOUT?
There's likely other ways the learning success will be measured in addition to Learning Objectives. Project Objectives contain Learning Objectives PLUS System Objectives (for e-learning: security, backup, availability, maintenance, ADA, etc.) , PLUS budget, time, audience constraints and other needs based on the stakeholders involved. You'll always need a few more Project Objectives in addition to the Learning Objectives.
Continue to Strengthen the Hands of the Strong!