This is in no way 'the reason'. THE reason is that using live data without having to bother with consent is 'fast, easy and cheap'. Having to get consent is seen as a nuisance, and num's the word as we don't want to wake sleeping dogs. And we don't want to pay for generating training data, so yeah, we basically just steal the data from our uninformed users without their consent. I hope the GDPR will pursue this as a landmark case.