Why New Catholic Encyclopedia declares trinity, a fictitious and pagan dogma?

The New Catholic Encyclopedia states: “The formulation ‘one God in three Persons’ was not solidly established, certainly not fully imilated into Christian life and its profession of faith, prior to the end of the 4th century. But it is precisely this formulation that has first claim to the title the Trinitarian dogma. Among the Apostolic Fathers, there had been nothing even remotely approaching such a mentality or perspective.”—(1967), Vol. XIV, p. 299.