Whilst I agree that the Thalmor benefit the most from the rebellion, it is hardly their doing in my opinion. It is rather the result of strict laws being imposed on the people of Skyrim by the Imperial authorities therein. The fact the Thalmor operate throughout Skyrim, under Imperial law, adopting questionable tactics and of coarse the manipulation of the whole situation by none other than Jarl Ulfric. Ulfric spreads his anti-Imperial rhetoric, thus sowing the seeds of discontent amongst his countrymen, however, as I've indicated on numerous occasions, the Empire makes it easy for him by their perceived indifference of the plight of Skyrim's citizens. The history between Skyrim and elves is turbulent at best and thus requires special care in my opinion and the Thalmor roaming unchecked throughout Skyrim, although legal, has taken it's toll on some of Skyrim's citizens. It would appear Skyrim grows impatient for the second Great War, perhaps the Empire should act soon, or risk Skyrim renouncing them, thus destroying any hope they have of victory over the Dominion. That is what I believe is at the heart of this rebellion.