$10 in 2011 would be $13.56 today.
Source: https://www.in2013dollars.com/us/inflation/2011?amount=10
Per the article, the service hasn't changed in price in 12 years, while the platform has certainly received a decent number of updates, new features, new artists, etc.
If it isn't worth $11/month to you, don't pay it? But it doesn't seem right to insinuate that they're doing something outrageous by raising prices once in 12 years?
Yep, there's a large contingent who simultaneously believe that corporations shouldn't be allowed to exist and also that they should be provided everything in life for free, as compensation for existing.
I'm not saying that nothing should be done to rein in corporate profits, as those are also out of control, but economic forces cut both ways and it feels disingenuous to suggest otherwise.