I am with google on this move.
First of all let us talk about the practicality of using someones mobile phone in mining bitcoin.
As we all know bitcoin mining is getting really hard even for this days most powerful pc's then here comes some mining app thru mobile that will tell you could do it with your phone.
Then along the way theyll ask you for payment in order to further improve the potentials of your mobile miner.
And at the end of the day youll just find out that you were just being scammed.
So much better to put an end to it in order to protect googles users.