Welcome to the forum
1) Why should companies adopt bitcoin in buying from their suppliers? Or selling to distributors? etc
Extremely low % fees, especially when dealing with large amounts of money.
Transactions that clear much faster than bank wires or checks.
After the first big sale, now they hold BTC which they can spent at a rapidly growing number of places.
2) Why should companies NOT adopt bitcoin in buying from their suppliers? Or selling to distributors? etc
Market risk when holding/selling BTC could be an issue.
In the future more companies will probably hold their Bitcoin as a valuable asset, but today there is still risk.