We have been trying to get the message out. However, it's a bit of a problem for a lot of people because, for various reasons, people don't want to invest in test kits (they don't know they exist, buying them is a hassle, dealers get pissed if you pull one out, taking them into venues is a bad idea, etc.). Getting good MDMA these days is an investment beyond the price of the pills. You have to think about the price of kits, the price of pills that you test as not MDMA, the oppertunity cost deals may carry if you demand testing, etc. It's worth it for sure, it's just that becoming that methodic isn't easy. Especially not during the honeymoon stage.
Dealers will keep pushing piperzines as long as they can. Make no mistake - dealers care about money and not about you getting piped or not. Finding a dealer you can trust is a lot like finding a gold mine, and they do exist. But even so, it's better to be safe than sorry. Get a kit.