Why is it that a total condenser and partial reboiler are used in a distillation column and it is not the other way around?
Partial reboiler is related to that fact that most times, there is material left in the bottom of the column. This can be because you need to maintain a level of liquid because the bottom take off is a purified stream you want (as product or waste treatment input) or there is not enough area to maintain the proper amount of boil up.
The total condenser is related to the fact that most times you want to condense the purified upper stream as that is the product (and since liquids have lower specific volumes than gases, it makes storage and transport more efficient) or you want a liquid stream into a second column or other downstream unit operation.
It is not a law of the universe that the partial reboiler and total condenser are the only way distillation can be done, but it is very common in current industries and so it is often discussed.