why vs it would be great if you can complete

Some examples from the web:

• I understand why you're so angry, Haley.
• But why? - To be myself again.
• But any child understands why we need borders.
• I wondered why you left me alone...
• Remember the five-year-old completely understood why Ivan took Joshua's sandwich.
• Theoretical physicists always ask "why" questions.
• Eichmann, probably wondering why your presence is required.
• I understand why you stopped believing.
• I see why employers are reluctant to hire ex-cons.
• Which explains why Samuel Henderson down in that bunker.
• Wonder why he just shot once.
• Now explain why you chose that size endotracheal tube.
• And why that accident report was faked.
• However, they cannot explain why.
• The Korean guy asked her why.
• And why these people took my daughter.
• Perhaps a little self-reflection might illuminate why.
• See why Deborah called five times yesterday.
• I'm curious why you requested this parley.
• I could never understand why Rathe wanted Waxflatter to stay.

Some examples from the web:

• But, it would be great if you can complete it earlier. Since we will share data with you electronically, you can work on it anywhere and anytime. If you intensively ...
• If you can't make the event then it would be great if you can complete the attached survey which will provide us with your experience and help us inform ...
• It would be great if you can complete our online feedback survey letting us know what went well and what we can do better for future camps. Your feedback ...
• Hi guys, It would be great if you can complete this survey for research purposes. It's a simple survey with less than 7 questions. Do help to complete the survey ...