Think of the world's and national trials as the Olympics of Schutzhund. You wouldn't expect the same high-level judging of gymnastics or figure skating at local events than what you would expect at a National events.
Correct, absolutely not (I used to live, eat, breathe gymnastics). Typically at the beginning of a four year cycle, scores at smaller meets (club or national meets) are all over the place (gymnastics rules change every 4 years after the Olympics and you think SchH/IPO rules are confusing?!? lol). Then they tend to settle but you will not see the same scores at club and national meets as you will in Olympic finals. In fact some competitions nearing the Olympics you will see deflated scores, they are trying to be as strict as they can and get the girls used to how THE event of four years is going to be judged. Depending on who the judges will be or where the event is taking place, the girls will alter their routines, their floor music, even their leotards and how they look to maximize the score. Technically, you *should* see higher scores at season-end events and the Olympics because those are the events they are training for all season or for four years (and especially at the Olympics it's important to keep the audience happy), but at the same time the judges are not going to do anyone any favors and if they are, they will be called out on it (like the 2004 Olympics men's results).
I don't see dog events any differently. To me, entering a national or int'l event is not just to earn a title but to compete
and for a competition to happen there needs to be a way of differentiating the results, not just pass/fail SchH3. It's not a competition if you've got 5 or so people tying for each placement. That is why I agree with judging big events being more strict and picky. The difference b/w gymnastics and SchH is not much but in gymnastics you take a start value into account and in SchH everyone starts from the exact same level (100pts), but given that, it makes even more sense that in SchH the scoring at a big event will be more strict, they have to be able to place people 1,2,3,4..... and the only way to determine those placements is the score.
At a club level event I would expect most entrants to be there to demonstrate their dogs can perform the exercises and earn the title, save for maybe a few people who are more competitive in spirit, or have a really exceptional dog, or have already earned the title and are preparing their dog for competition.