5% false discovery rate is true if the apriori probability of each result is 50%. If a journal wants to publish only surprising results, and accepts p=0.05 with a good methodology as true, it will have higher rate of false claims, because the most interesting things are more surprising than a coin toss.

And if you slice the data from a single experiment in 40 independent ways, your chances to get something with purely random significance p<0.05 are better than 50% for a single study…