It's all for personal reasons!
He resigned as manager after eight years.
She resigned from the government last week.
force sb to do逼迫某人做...
A: Sir, I want to resign from my Sales Manager job. Here is my resignation letter.
B: Why are you quitting so suddenly? Do you have any complaints against the company?
A: No, it's all for personal reasons. I've been feeling too much pressure recently. I have insomnia and migraines.
B: In that case, I won't force you to stay. I hope to work with you again in the future.