However, I personally will never use their service again. When they thought it was alright to use my network (that I pay for) to make money, then I have a right to turn my back on them.
Questionable legality is one thing, I personally could care less about laws. I break probably 5 or 6 laws an hour. Laws have nothing to do about morality. It's "illegal" to go 1 mph over the speed limit, it's "illegal" to cross the street without a sign, etc. As a society the vast majority of the laws we don't care about or follow.
What most people do is try to be moral and civil with one another. In the case of distributing music, most people seem willing to pay (hence Spotify has become popular). However, that didn't give them a right to use my network without my consent.
That is immoral, and that will get a visceral reaction from people. In this case, it didn't surprise me they were using torrented content in their service. I shared what I found interesting, and why it didn't surprise me, and also my opinion about how they were shady.
> even though they've since entirely removed that functionality?
If a company is shady, I'm not going to trust them with my money / data unless I have to (i.e. Comcast / Verizon / AT&T). If I have a choice, I'd use someone else. This is my "vote" of dissatisfaction. I vote with my wallet, and I share my insights / knowledge such that others will vote (informed) as well.