The founding fathers know that political parties would lead to the downfall of America, so why did the set the bar so high for impeachment?

Simple majority?  By now you'd have had 30 presidents removed from office.

Wow you are a hot mess of historical revisionist nonsense.

First, George Washington was actually offered a 'lifelong sovereignty' for his spectacular military displays during the Revolution and it was he who turned it down and set the precedent of two terms in office. This was not law until FDR broke with tradition and tried to permanently install himself, successfully running for a third term and possibly fourth term had he not died first.

That is when the 22nd amendment legally set the term limits for the President to two terms of four years. 

So our founders never 'feared the arrival of a king' and even invited it and fully anticipated it. They believed that liberty could always be maintained by our system of 'checks and balances' which restrained any form of exerted power using an existing counterpart or creating a new one, if necessary.

Second, a '2/3 majority' is an extremely high standard for a jury since ALL other trial juries are required to be unanimous. When even one juror dissents, this is called a 'hung' jury and the person is either acquitted or a new trial is set and the person is retried. This standard is so high because this is our Chief law enforcement executive on trial. Making it even higher, (as you suggest a 'simple majority'), is completely absurd. 

Donald Trump was EASILY acquitted because he is innocent of the ridiculous charges. My greater concern is the abuse of power by the House in failing TWICE to level charges worthy of so great an insult to our chosen leader, especially since his only 'crimes' appear to be trying to expose corruption by the man in power now, (Biden's activities in Ukraine and China, the first 'impeachment'), and the complicity of the Press and our bureaucratic agencies in covering up a stolen election, (the second 'impeachment').

The most disturbing to our founders would be watching a man installed into power surrounded by a standing army that had to be 'cleared' first by a clandestine police force because the people were enraged at HOW he came to be elected. 

a king would cause issues (i mean people think the british royal family are useless), so a president is like a prime minister mixed with a king/queen. the problem is, the same people who vote for the president thought corona beer gave you coronavirus. you see, political parties arent the problem...

The Downfall of America is Joe Biden and his democrats with their Prince of the Power of the Air.