I can't think of a technical reason (besides the GL segment by warehouse option you mentioned... and the question of whether the updated warehouse value should get pushed back to the PO line as the receipt is posted...).
The idea is probably that you want to enter multiple lines in the PO for an item, if partial quantities go to different locations (so the printed PO can direct the shipments to the right places).
You might also want to consider Master PO, creating Standard PO's at the receipt stage, with just the quantity being received, for the correct warehouse. Easier to reconcile the individual shipments that way... depending on the invoicing strategy.
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Kevin Moyes
Technical Systems Analyst
Munjal White Consulting Co.
Toronto ON
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