More likely because the former president did not want the current president to have a win. Usually, most former presidents what the country to succeed and get stronger. Not "the Donald" which aligns with his track record.
Remember, Mr. Trump decried the infrastructure bill before it was passed, months ago, before any pork was identified.
Funny, for a man who wanted to have an "infrastructure week" which never came during his 4-year term, trying to stop the bill before it passed says it all!