KesselMania has a point in that this didn't happen in a vacuum. This situation is the logical outcome of a path that UEFA itself embarked on 30 years ago. Of course, already back then it was to some extent the result of blackmail by those big clubs. Every single reform of the European Cup has been driven by blackmail from the 'big clubs' who wanted more revenue out of it. Heck, some of those clubs who kept pushing aren't even in the "club of 12". That blackmail only worked because the appearance of commercial TV on the scene. It's the deregulation of the media in Europe in the 80s that really has driven it. Without commercial TV stations, without Sky etc., the PL doesn't exist, the CL doesn't exist, and most people on this forum would likely never have watched a foreign league game.
But of course it was the public which clamored for more football on TV, more entertainment. The public that was interested in seeing 'the best' and wanted to see Man United play Real Madrid and Barcelona and Bayern, not go through Slovan Bratislava and IFK Goteborg before going out against Steaua Bucharest (just as a hypothetical example). The European public isn't any wiser, they focus on the 'haves' not the 'have nots', just like Americans want to see the Lakers and the Yankees. Of course, at no point did anyone think it'd go this far. It's death by a thousand cuts or the proverbial frog being boiled slowly but surely. And by the time things got this serious it was too late.
But make no mistake the only way to rein this in is to bring back what originally kept things under wrap in the first place - regulation. Not by UEFA but by political bodies that can actually back their edicts up with the force of the law.