I always recall Sierra's research that indicated a fairly small percentage of its customers actually ever FINISHED their games. Telltale's model, especially on platforms that sell individual episodes, probably does get pushed towards ease more often than not. For creative as well as commercial reasons -- after all, no designer wants to feel like all the hard work on a story's dramatic finale won't actually be seen by a substantial chunk of the audience. A player who gets frustrated and gives up is not likely to return, and if that player is altogether new to adventure games then we're all poorer for it.
On the other hand, we all have different pain thresholds for difficulty and the types of puzzles that annoy us, so it's very hard to create something that provides the "right" level of challenge for everyone. I tend to get stuck on my own bad assumptions -- I think I've already looked in a cabinet or explored a path when in fact I've missed it altogether -- so a subtle verbal or visual reminder or hint is often much appreciated.
Maybe one path to a better future could rely on the idea that different types of adventurers also have different expectations about what constitutes "victory" -- there are ways to let a casual player experience the whole story by stumbling through it, and reward more serious players for finding better solutions to the puzzles as was done in the early KQ games. (The bronze/silver/gold medal system in Jurassic Park was a simple but effective way to do this -- you need to meet a minimum standard, but needn't master every scene to progress. But that's easier to measure in a QTE context.)
The art of interactive entertainment needs to keep evolving -- I just finished playing Roberta Williams' "Mystery House" for the first time last night, and was disappointed (SPOILERS!) that I was not penalized or admonished for stabbing Joe the Gravedigger myself and stealing his shovel, which was wholly unnecessary as it turned out, instead of letting the villain take care of him and maintaining the moral high ground. On the other hand, I couldn't just run off with the jewels and claim victory, I had to find the gun and shoot Daisy myself to be declared a WIZARD GURU.
Notify the media! ROBERTA WILLIAMS FORCES YOU TO KILL PEOPLE!