This service may serve a purpose for men as an early indicator that their SO has communication issues. I cannot speak for anyone else but I for one would not want to be in a relationship where my SO was spying on me like she was my probation officer.
It is to some people - I know I'd be bothered by it. Mostly due to my own insecurities. I'd wonder "Why?", and wonder what I'm not doing that he wants.
For some it might been seen as a light form of cheating.
I think that it's a sensitive enough topic that if you're doing it without your partner knowing that you're likely treading into a potential problem.
(For the record, I feel like searching your partner's computer for anything is a gross violation of trust - more so than watching porn without the other person knowing)
It depends on what kind of relationship you have. Traditionally, and what seems right to most people is a relationship with a level of commitment towards the other. I'm not saying this is always true, but that level of commitment does have benefits, usually resulting in a stronger relationship because of the trust developed.
Associating watching porn with lack of commitment sounds like something out of the 50s. Nobody(*) contemplates leaving their SO for some person on a website (or in a movie, or on TV), and porn isn't an exception.
But actually, I wouldn't be surprised if somebody broke off an existing relationship to pursue someone they were fantasizing about online. If they're unhappy in their current relationship, online fantasy is a form of escape and leads to eventual idealization. By comparison, the real person can't compete as their flaws are evident.
Dime-store psychology perhaps, but on these topics nothing surprises me.
Probably closer to more like something out of the 90s. Also very much age / culture / internet age related.
I think many of the attitudes regarding porn has changed simply because it became so ubiquitous that it changed culture, not that culture somehow grew up and grew to embrace porn.