Trudeau only wanted an electoral change that would guarantee Liberal majority governments.  The Conservatives would accept any change that was approved by a referendum, but the Liberals rejected that approach.  After all, you can't have democracy interfering with democracy.
Of course, as a majority government, Trudeau could have passed any bill he wanted, but it would also have meant going against his fellow Liberal MPs who dominated the Commons Committee on Electoral Reform who recommended the non-Trudeau approach.
Now, let's all say the Trudeau speaking line "It's not my fault".
So much for responsible and accountable government - Trudeau and the Liberals represent neither.