Not a recent thing, if anything things are getting better over time, just slowly. I remember reading stuff about how "forensic science" has been the realm of quackery for as long as I have known how to read.
Police are incentivised to find whatever thingamajig will support their conclusions. Courts are not equipped to provide meta-review of every forensic claim. And for the bright, rational, scientific minds out there, working in forensics is relatively low-prestige and low-pay.