Because it could have been Billy Batson and the Magic of Shazam. It could have been DC Super Friends. It could have been Tiny Titans. It could even have been a sampler of pages from Wednesday Comics.
It could have been something that an uninformed parent, lured into a comic shop he or she has never visited before by the prospect of "a free comic for the kids" would be pleased to actually give a kid, and the kid might enjoy it and want more such comics.
No danger of that happening here. Instead you offer them a grim exercise in impenetrable continuity porn. Excellent job, DC. Once again you've succeeded in warning off new readers by giving them a realistic idea of what to expect from you.