It is normal for any dictator and his elite to seek any kind of revenue from everything, from faking goods, selling counterfeit currency, involving in smuggling, everything till...anyone dealing with this is seen as gathering too much power and the thing is considered to be dangerous to the foundation of the party and terminated.
If Putin decides this thing could give too much power to somebody and be outside its total control it's game over!
watch this snippet from an interview with putin: https://twitter.com/APompliano/status/1255160696461037574
putin understands very well that russia can't control bitcoin. the central bank also recently acknowledged that a ban is actually impossible: https://beincrypto.com/russian-central-bank-admits-it-cant-ban-bitcoin/
a ban on bitcoin would be like a ban on gold---unenforceable, and would make the government look very impotent. these conflicting bills that keep being proposed are IMO more about political posturing and power brokering than an actual ban.