In my copy of this book, at least, we can only speculate about how Muhammad actually felt about merchants. We know how he behaved towards some merchants, but not how he felt about merchants as a class.
We can infer that Muhammad did not have anything against merchants as a class. The reason that we can infer this is that he himself was a merchant. Muhammad’s marriage to Khadija allowed him to become part of a prominent merchant family. He then made money for himself as a merchant. This implies that he would not have been opposed to merchants in general.
However, we do know that Muhammad did not get along with a certain class of merchants. We are told in the book that Muhammad came into conflict with the wealthiest merchants in Mecca. He “denounced greed as moral wickedness” (p. 207 in the brief Second Edition) and that made the merchants feel that he was attacking them personally. They also opposed him because his attacks on idolatry were an economic threat to them. They made money from people who came to shrines in Mecca. If Muhammad succeeded in getting rid of idolatry, they would lose that money.
What this tells us is that Muhammad did not get along with the richest merchants in Mecca. However, we can still infer that he did not dislike all merchants as a group.