Actually, I am saying it is rewarding for some time (60 more days till Fractal God). But none of those things are of monetary value by themselves. Not like you can cash it in to build legendary weapon. They just decreased likelyhood of continuing doing it after finishing the long term goals. Or whether I will want to suffer for 60 more runs to acomplish them.
And yes, I am saying they are boring. The same way of boring as all the strike missions that are there... same as d DRM are... and the non-CM fractals... (fine I like uncategorized fractal, but that is an exception). Maybe strike CMs will be more interesting, but if there is no better reward than from regular ones, or if it is one-time reward like from Raids? That is one run and I am done.
I am not saying the bosses will not have interesting mechanics, or there will not be interesting backstory. I am looking forward to it to play it few times. But if it is aimed at casual players, 3-4 runs and I am done with it. Forging steel is really good story and events, I like it the most. But you can't fail, you can solo it, it just takes eternity and for what reward? Having challenging content with no reward is boring to repeat, having boring content with good reward is also boring to repeat.
You probably never did fractal CMs, right? You have never felt that "Nice!" moment when you opened the chest and saw those 2 or 3 coins appear there. Integrated matrices? Fine, I will flush them down the Fractal God toilet, 150 Blade shards? Ok, I guess I will craft 3rd spinal blades pack. With MC, you knew you are few more coins closer to your next legendary.
What they are saying is "You were doing something challenging and sometimes received something nice? No go do a casual content and you will get it 100%".
That is another factor in it. MCs were random. You never knew you will get one. You were not expecting to get it, but it is really nice feeling when you get some. Even going as far as "racing" who will get more MCs on that day, who is more lucky. Being told that I will get exactly 10 each month when I do this amount of strikes? It takes away the surprise. It takes away the feeling of being lucky. It turns it into a chore.