I gather they received a lot of complaints from people about phones being damaged or being rendered useless by these Apps, or they would not have reacted this way. Anyone that tried these Apps before, would tell you that it is useless and the battery and resources are hammered, without any result in the mining.
Mobile phones should never be used for mining, even if you are only going to mine some worthless Shitcoin with it.
Why would you "kill" your phones performance, for a gain of a few cents?