But really, the articles spell out that power creep is the intention of the MIC. In the first article, Andy searched for and clearly identified the top six "most cost effective items in the game", and in the second article explains that every item every item in the MIC "had to compete with the top tiers of items". Think about that. The goal was not to create items that were useful. Average wasn't good enough. The only way an item made it into the MIC is if it was the best.
Compared to the 250+ items in the core rules, each item in the MIC is designed to be better than 98% of them. If that's not power creep, I don't know what is.