It's Only Money....
There is no difference between using a jumper bar on the speakers and connecting the two wires of a bi-wired scheme to the same terminal on the back of the amp. It is still a parallel electrical connection between the high and low drivers/crossovers.
I've heard the argument that using two wires will decrease the total wire impedance and electrical losses through the cable. But I challenge anybody to open up their amp and look at the wire connected to the inside of the speaker terminal. That internal wire is the weakest link. There is no gain by running one cable of a larger gauge or running two cables for a parallel load compared to that internal wire.
As was stated before, bi-amping is another story. Now the driver loads are divided between two amplifiers.
BTW- two 8 ohm parallel loads will give you a 4 ohm total load. Two 8 ohm loads in series will give you a 16 ohm load.
Now everybody start playing nice