According to you folks, I “accept” the risk in both cases. Why is it ‘right’ that I am entitled to compensation in the first scenario but not the second?
In the first scenario you're travelling as a fare paying passenger and therefore are covered by the Civil Aviation Carrier's Liability Act.
In the second, you're not a fare paying passenger (assuming it's not a charter flight). If in the second scenario it were a charter flight then you'd receive (strict) liability protection