We can make this simpler.
I too find that some checks are designed to be failed. I've played the game a few times and found that I fail some checks consistently, over and over again, regardless of modifiers, regardless of how many times I try, my rolls are low.
Fine. That's not enough data on it's own to determine a pattern in the data. The larger the player base, the more likely it is that odd things will come up for infividuals. But that doesn't disprove that there's a pattern either. We're still stuck with a single piece of anecdotal evidence. But you know what we can do from there?
"Hey, everyone. I'm experiencing this weird phenomenon. Is anyone else experiencing this, or am I just unlucky?"