It is not a given that it is best for the buyer to acquire assets. There are some things that work in buying stock. For instance, large NOL's, large business credits and the buyer can use Sec 338 to treat the assets as if they were purchased separately. Also, if the assets are encumbered, or are being leased, such assets under asset purchase would have to be negotiated with each lender/lessor individually.
There are so many variables in a buy/sell arrangement that each option has to be looked at carefully.