just my two cents,
Every Aircraft has a certified landing weight which may be due to structural, runway, or any other limitation, But there are times when the Max take off weight is higher than the Max landing weight.
So you have to burn off excess fuel to lose weight, rather than throwing the Self Loading Freight. If the aircraft lands more than the certified max landing weight, then... it would be a bigger accident and maybe structural failures, harder landing, landing gear breakage or etc..
hope it helps...