I think you have hit upon one aspect. Napoleon is one of history's Great/Bad men. The very fact that he personified a political entity makes him open to any critique being interpreted as a personal attack. Policy arrived at collectively, either democratically or by an oligarchy, doesn't have quite the same sting when crticism is applied. Some 'modern' apects, such as a unified Germany, does not yet really exist. German contingents fought on both sides. This muddies the water somewhat. Of course, the personality cult that was (is?) Napoleon was carefully created and nurtured by himself, so in that aspect I would contend he had only himself to blame. After all, he is perhaps the only individual in history that nations have declared war on. There is much evidence that he saw himself as an ascending star. But as in modern celebrity, what goes up, must come down. In British culture, building people up to only tear them down again has almost become a national pastime.
I think it is also worth distinguish policy within/without Europe. Outwith Europe, with the exception of the German states (who seemd to have their hands full with each other) most entities' empire building remained much the same. No one seemed averse to the odd Spice Island or two and had varying amounts of empire beyond the sea to profit from. To put that all at the feet of the British is just punishing them for being more successful. Before our US cousins start tutting here, I humbly refer them to the Spanish Amercan War and Peurto Rico, Guam, The Phillipines and Guantanomo.
Continental acquisitive behaviour was and is very different. Being an island race, the British have a different perspective. Other more recent experience of acquisitive continental personality cults, particularly one perpetrated by a Bohemian corporal, undoubtedly colours opinions somewhat. It's not Napoleon's fault that his actions are seen through the lens of a thoroughly more evil European empire builder, just an accident of history.