No, it is not about saving the environment. As I said, there is next to no margin in selling music online. Just look at how many companies have tried and failed. Only Amazon and Apple have succeeded because they have other things to sell to make money. To that end, anything that reduces costs is important and MQA does that for high-resolution audio.
Without MQA, we are pumping out tons of useless data as there is very little useful info above ultrasonics. And what is there doesn't need 24 bits to describe it. Or even 8 bits in many cases.
As to why go after Stereophile, high-resolution audio in the form of MQA or PCM is a very hard sell to general press. It is not a mass market offering so you have to go to vertical press that has affinity for it and hence stereophile. It also doesn't hurt that stereophile knows Meridian, Bob Stuart, etc.