Why did it take a coup?

My only irritation is over the question of why Yingluck wasn’t impeached while in office. Why did we need a coup and then impeachment by junta-invoked zombies? This is like killing a bird in a cage with a sawn-off shotgun and ecstatically giving each other high-fives. It seems every time a government’s popularity surges, we get blank TV screens and patriotic songs. The same thing happened to the governments of Chatchai Chonhavan and Thaksin Shinawatra.
Meanwhile, let’s make a law that requires chiefs of the Army, Navy, Air Force and police to take an oath to preserve, protect and defend the Constitution of the Kingdom. Let’s modify the country’s motto to “Nation, Religion, Monarchy – and Constitution”.
We have been treating the Constitution like a pair of old shoes, throwing them away and getting a new pair on a whim.
Somsak Pola