The phrase "distinct lack" means a clear absence or shortage of something. It is an idiomatic expression that emphasizes the severity and noticeability of the deficiency in question.
There has been a marked slowdown and distinct lack of high end Android tablets of late. (slashgear.com)
A dull course, with an annoying hazard and distinct lack of charm. (videogamesuncovered.com)
(In light of this film's quality and Jennifer's Body's distinct lack thereof, it is high time to reevaluate how much of Juno's success was due to Reitman's direction and how much to Diablo Cody's script.) (theatlantic.com)