Lieber is a proven consistent journeyman starter. He plays for a good team and pitches a lot of innings, which equates to good number of wins.
He is far froma #1 or even a #3 fantasy pitcher, but I do not see how can be dismissed as junk, even if his K rate and ratios are not so hot. At the end of the season he will put up his usual solid but unspectacular performance. I would say that he is not WW garbage in a 12 team leage now and surely will not be by mid-summer by another 10 SPs are on the DL.
I will always be happy to take a guy like Lieber to fill out the last SP spot on my roster. Over a full season, you will typically do much better with this approach rather than trying to catch lightening a bottle with a "hot" starter or the flavor of the month 24 year old.
Who is on your WW that you are so eager to pick up for Lieber?