I think what it boils down to is that it's just a low priority for them to fix, versus working on their products. They probably have a fix in the works as part of some new redesign and have judged the current annoyance to not cost enough money to fix immediately. I'd chalk it up to incompetence versus malfeasance.
This has gone on for too many years, and makes them too much money, to be a mistake. They completely ignored and refused to acknowledge the original subject of the thread, which states explicitly: "how to cancel monthly subscription to photoshop? Website leads you in a loop".
I don't think Adobe's incompetent when it comes to maintaining their own web site. It's the business they're in, and what the tools they make do.
So to be charitable, I'd chalk it up to competent malfeasance.
But on the other hand, maybe they're suffering from eating their own dog food! Perhaps ColdFusion web sites are so buggy and hard to maintain that they can't even fix their own infinite looping problem after all these years. Perhaps it's so hard to hire competent ColdFusion programmers and interaction designers, that even Adobe doesn't have any on staff.
Maybe like Valve / Steam they do it because they can... until someone with a lawyer drags them through court and they're held accountable for building theft and fraud into their business model.
Before it even went to trial they globally overhauled their refund system, presumably after realizing EU, USA, CA etc also have consumer protection laws designed to protect consumers from companies that are committing fraud.
