Physical attraction is a bit over rated. If it was so important then beautiful couples would never divorce each other
Average looking and below average looking couples can get divorced as well.
Even if looks were not taken into consideration........other issues such as incompatible personality can be the cause for divorce.
Nobody is saying that physical attraction is the be-all/end-all in a relationship. But it's not unreasonable to say that this aspect has its onw unique and important place in a relationship.