Financing Contingencies

why would a buyer not accept such contingency?

Buyer should always accept this contingency. Unless all cash offer is in order.

because getting a mortgage is actually hard these days, sellers may not. Especially with jumbo loans which remain on the bank balance sheet and do not get purchased by any of the govt agencies. This as well as the appraisal can wreak havoc on your purchase and thus sellers sometimes will deny an offer with financing contingency.

Depends on the situation and who has more leverage. In a seller market, it will likely cost you to have a contingency (higher price)

Right now it feels like market is bifurcated, desirable, right priced properties are flying quickly and won't take contingency.