Luke Negative on block

Im a luke main hes the only character I ever spent time to learn and im probably just garbage. But I was looking at his frame data and all his moves are negative on block. Like is that normal? Seems like no matter what I do I get grabbed out of a combo when their blocking. Im only aware one move of his is positive on block 2MP I think. Just want some insight on how to apply pressure with luke from some dope luke mains. Thank you