I will preface this by noting that I have never met Tomas Verner and this post is therefore pure speculation on my part.
Anyway, here's my theory: Tomas Verner has been skating senior internationals since 2001-2. I'm not sure he even had much of a junior career before this; he was 15 years old at his first Europeans*. For his first five seasons as a senior, he did not accomplish much outside the Czech Republic. He was never higher than 10th at Europeans or 13th at Worlds. He did not qualify for the SP at 2005 Worlds, which we can all agree was not really an event that featured great skating among the men, and then followed that up with an 18th place finish at Torino Olys. In short, he was, for an international senior-level skater, average.
I have no memory of Verner as a skater during that part of his career, but at some point in 2006 he must have had a breakthrough, because by 2007 he had turned - seemingly overnight - into a top-level skater. His technique and presentation are wonderful and his personality, as comes across on the ice, is very likable. I think even those who are not fans of his can say that when he is on, Tomas is very deserving of his success. What I wonder is whether Tomas himself has actually adjusted to being one of the top skaters in the world, with all the attendant expectations and pressure. My guess is that he hasn't, and as long as this remains unresolved Tomas Verner will remain inconsistent.
*ETA: According to his Wikipedia page, he won some medals in JGPs in 2003 and 2004, and competed twice at junior Worlds, with his best result being 14th place in 2004.