If we go back 4 years, the very start or IPO if you like for BLK there was direct mining (long over and completed pow phase) but now POW is unused unless we are talking in slang for staking (POS) which does give extra BLK to users/holders (miners if you want to label it comparatively like that). Its possible people would confuse the two.
The old bitcoin wallets used to be able to 'mine' new coins but to do similar with BLK you'd have to have a balance of BLK in the wallet first place to stake and then you get a kind of interest is how I see it. I wouldn't argue too much if people want to start calling it mining. BLK isnt using GPU
The other thing would be to mine completely separate blockchains and then buy or exchange the mining proceeds into BLK. Good idea because it can be staked and staking will not interfere with operation of a GPU so it could be considered similar to mixed mining in a rough way.
this video is interesting and mentions POS. I did not know the staking original idea predated bitcoin usage
https://youtu.be/6xIq0FdmsIA?t=1572
See I dont agree with this guy exactly but he isnt using absolutes and mentions big known problems to me which is good for starters even if the conclusions are 'meh' as he says. The big deal is staking is more efficient then all the energy used up by bitcoin and I think that could be make BTC secondary even. Most economies are centred around competitive markets and efficiency, it will matter but maybe BTC improves