"He tried law instead but found that insupportably dull and finally managed, more or less by default, to aquire a degree in divinity from Cambridge."

I've asked about default before, but the default thing still isn't clear to me. I've tried to find out by searching net and dictionary. No way.

Could one of you kindly put the "more or less by default" part in other words so I may at last understand?

I think it is meaning "by default of something better". Is that correct?