All games are 'artificially' difficult. Dodging is a skill in and of itself. If you can't dodge, you don't have the skill for this particular encounter. Sure, memorising the pattern rotation will help, but it isn't necessary. I still don't remember the rotations, even from HM, because it's not something I need to do. You just need to know how to deal with each of those patterns or events.
If you are expecting a stellar turn out in a Duty Finder with no implicit demands on previous experience or performance, then you'll likely be disappointed. You have three choices to succeed:
1) Take a group who you know can all do the fight
2) Take a group with players who can carry those that aren't great at the fight
3) Take a group with players prepared to put the time in together to learn
It sounds as if your base reference is number 3 and this is always going to be the most difficult option because it's ALWAYS the situation that DF is in and ALWAYS the situation DF doesn't want to be in. But it's ultimately the player's choice. Although it's good the option is available, I don't think the DF is how Titan Ex (or even HM) is primarily intended to be completed.
Groups in i80/i90 are not struggling to complete this fight. Groups with multiple players still unable to dodge the abilities and deal with adds and tank switches are struggling to complete this fight. There's a difference. Yes, running Titan Ex in shitty gear is probably a bad idea. Whoop dee doo. But I promise you that the reason players fail is, for the most part, not because of gear.
You keep insisting the only way to have valid difficult content is by making it based on decision making. You like one type of content, we get that. But not everyone consistently likes the same thing. I personally like variation and that my skills are tested in different ways. Decision making is certainly one of those, but being able to perform a dexterous role while under intense pressure is another.