Who knows what the original play store apps did to begin with. Most of the top apps are basically malware. Maybe someone added a bitcoin miner to the existing spyware that came from the original app but it just comes back to the same thing that you can't trust proprietary software to be safe.
But at least if the original play store apps have spyware issues, you can generally find a developer/company behind them to blame. If Google updates the Gmail app to include a bitcoin miner, people are going to find out and be pissed at Google.
If someone takes the Gmail app, injects a bitcoin miner and uploads it to a third-party store, who gets the blame?
