It should not be illegal, as an individual, to hate or express hate towards others, or to make politically-motivated buying decisions in the free market. However, organized political boycotts like BDS are not mere hate, they hurt Israel and harm America's national interests. It's not about speech, and it's not only about Israel, since the bill applies to other friendly nations as well.
What products an individual chooses to buy or not is their business. Leading or participating in organized, politically-motivated boycotts is harmful and subversive to the national interest.
Which Americans actually benefit from the "national interest?" Why should it be a felony to not support a foreign government? What about America's government policies that are hateful towards Palestinians?