With only two days left in the first quarter of 2015, CNBC's Jim Cramer said Monday that the quarter was poor mainly because of one factor: poor earnings.

"We came in with such optimism, and the earnings really hurt us. A lot of that is the strong dollar, but the earnings have been … disappointing. I think the averages have really reflected that," Cramer said on CNBC's "Squawk on the Street."