For the median American that works full-time, who earns around $56,000, the cost of Spotify is 0.2% of their income.
Obviously everyone is in their own financial situation and for some people that will still be a burden. But for sake of comparison, in 1989, the average cost of cable TV was $18, and that's of course in 1989 dollars. I don't think it's unreasonable to say that $11 for unlimited access to basically all music at any time is a pretty good value for the money.
That said, if it is still onerous to someone, they're obviously not in ideal circumstances and I'm really not gonna fault them for just pirating.