It's possible that the odds are not as stated, but the way to "prove" it isn't by pointing to specific cases. We obviously tend to notice and remember the extreme cases (like the ones you listed but also things like "I yolo'ed this to 15 stars in one go!") You would need to collect data from thousands of star-forcing attempts, including all the boring ones where the results were as one would expect, to be able to deduce the "real" odds.
That said, Maplestory's random number generator sucks. I'm talking from a mathematical point of view. It has a tendency to "cluster", which means giving the same or similar results if used in rapid succession.
That's how you get people failing star force (or, for that matter, 70% scrolls and 80% potential stamps) many times in a row - but also how you get people passing three 10% CSS in a row.
So I always advise people not to spam attempts if they're failing. Take a break, change channel, go kill a few mobs, let the RNG get out of its bad mood, and then try again.
Oh and @Neospector since you brought up the Noble set, could you tell me if the Maple Galaxy equipment set is similar in that you can't move the items to the cash shop? I'd love to get them, but if they only clog up my inventory I'll probably pass.