Why?
Well, it is true now, but at the start of the Reformation there were priests who were still properly ordained (and could still confect the Eucharist). Over time, however, those priests died and the Old Rite was changed so that it was no longer a Catholic Rite. As a result, the New Rite became invalid and did not ordain true Catholic priests that can confect the Eucharist.
To my knowledge (and I may be wrong) they don’t believe in transubstantiation.
After the generation which defected from the Church died the reformed churches lost their Apostolicity. That is the direct line of Ordination from the Apostles. Catholics and Orthodox priests are all ordained by a Bishop who was ordained by a Bishop who was ordained by a Bishop, etc. all the way back to the Apostles who were, of course, ordained by Our Lord Jesus Christ.
Most Catholic priests in the US can trace their Ordination to St James since he established the Church in Spain and France, which later sent missionaries to America.