And yet nobody condemns the original trilogy as bland.
Except they do. I do. There are many people who don't like Star Wars because of its simplistic good vs evil story. I like Star Wars, but I don't for one second think it's the epitome of story telling. Basically, what you're telling me is that you want Star Wars to always be the exact same story over and over again with basically just name changes here and there.
How do you know the senate was corrupt? When did any Jedi do anything "outside the system"? Seriously, work it through: how is the Republic corrupt, apart from the bare fact that Palpatine wins in the end? How is the corruption substantiated? It's pretty obvious that Lucas wanted the Republic to be corrupt, sclerotic, superannuated, bureaucratic, whatever, because that's the trope. But, he never really showed how it was, or why.
Funnily enough, you answered your own criticisms in your next paragraph. The word of the Queen and two Jedi weren't enough. All because the Trade Federation senator denied all the allegations. THAT is your substantiated corruption and bureaucracy. How much more do you need? As my parents love to say: do you need me to draw intestines on a stick figure?
And despite this, Senator Jar Jar, with no real opposition is able to propose the creation of an army and the senate straight up and does it with no debate whatsoever. They seem to be really efficient when they want to be.
Again, THAT'S THE POINT. Ordering a non-partisan investigation as to what's really going on? Obstructed. But the creation of an army that merely benefits the military-industrial-finance complex? Immediate effect. That's the corruption you're looking for. How much more hand holding do you need before you learn to put two and two together? I wonder if people who criticize the prequel even understands how bureaucratic corruption works? Do they even see that is how the many modern governments, including the US and the EU works? Sensible things are obstructed all the time, but bad ideas that make a few people rich could not be greenlit fast enough.
Are you kidding? The Empire kills everybody on a little ship they easily overpower; Vader snaps the neck of a rebel subaltern just because he doesn't know what he wants to hear; the Death Star blows up Alderaan and nearly destroys the moon of Yavin. Tarkin flatly states that the fear of his battle station will oppress the entire galaxy, and orders the death of Leia's family, friends and planet right in front of her.
No I'm not kidding. By that point, you're ALREADY on the side of the Rebels because you've been told the Empire was evil. Think about how you would interpret the scene without seeing the opening crawl. Sure, you may still side with the Rebels, but that's because it starts off being a David vs Goliath battle between ships and you're socially conditioned to root for the underdog.
But nothing about any of those actions you've mentioned are evil (after disregarding the exposition of the crawl) UNLESS you're willing to imagine something outside of what is shown in the movies. Something you no doubt reflexively did and have no apparent trouble accepting when watching Star Wars, but hold a double standard for when it comes to the prequel.
Hell, in the current political climate, it's not so far-fetched to think that if the opening crawl switched the evilness of two sides around, a sizeable proportion of the American population would side with the Empire thinking they were the good guys. The Rebels? TERRORISTS. Alderaan? AL QAEDA. They even both begin with "al". Or TALIBAN. Because they sort of rhyme. Yavin? IRAQ. Bail Organa? BARACK OBAMA. Many Americans would love to see that hippie-on-the-outside-terrorist-on-the-inside dead. He probably even faked his Alderaan birth certificate to hide the fact that he was born on Korriban. See how many things you just plainly assume and accept by being told?
When does, say, the trade federation do anything of the type? They blockade a planet, but nobody on the planet actually seems to suffer. They demand a treaty signed, but we never actually find out what the treaty is for, or what it entails. And they're in cahoots with Sidious, but we have no idea what they actually have to gain from the dispute. I guess it stands to reason they have to gain something, but there are no stakes, there is no drama.
Do we actually need to see the suffering? References to the suffering were actually made throughout the movie. If being told which side to root for in the opening crawl is good enough for you, then so should being told they were suffering without being explicitly shown is also good enough. In fact, all your objections about the why's and how's of the Trade Federation are answered in the opening crawl for the Phantom Menace.
Lastly, no doubt you've seen the Family Guy spoofs of the original Star Wars trilogy. Seth MacFarlane loves Star Wars, but even he (and the other writers) quickly tore down every piece of bad plot and writing. To pretend that the originals were watertight is ridiculous and shows the predetermined bias against the prequels. The prequels were not the best movies, but they definitely kept in line with the originals. The only thing elevating the originals is people keep looking at them with Han-shot-first coloured glasses.