The other side of that coin does not become apparent until you have driven a 59. Compared to the other tier 8 tanks, a Type 59 is slightly slower, with a tier 7 gun and some pretty serious weak spots in the armor.
Sure, the sloped armor offer some benefits that only a few other tanks can impart, but once you figure out where and how to shoot them, they are no different really than any other tier 8 tank.
Does it take skill to kill them? Sure... it takes a bit of skill, but so does killing any tier 8 tank.
SO what is the problem with them? Well, for starters, the matchmaking system is screwed up in a variety of ways, not the least of which is failing to establish parity of 59's. Often you will see one side with 3x as many as the opposing side.
But here is a funny irony. At least from the experience of THIS 59 driver, the team with the 59 overload ALWAYS loses. I have been on both sides of this scenario so many times it is pathetic, but check this for a while and you will see.
Another problem is sheer numbers. When WoT needed an influx of quick cash recently, the declared that the 59 would be removed from the store after a certain date. Everyone who was clever enough and rich enough and did not already have one, immediately went out and bought a Type 59.
So.... now they are even more common than they were after they were first introduced. It will calm down, eventually, but there is no tank (except perhaps the more expensive Lowe) that can generate credits like the 59. If you have other tier 8 tanks, you will need some sort of credit generator like a 59 or you will quickly go bankrupt.
That brings up one final "problem" with the 59. They are so cheap to run and lucrative even in a loss that people tend to drive them more aggressively than other, WAY more expensive tier 8's. Thus, you will see a pack of them, or even in ones and twos, roll over and through other tanks as though they are invincible. They are not, of course, but it sure feels like that when you can still clear 10k credits in a quick loss.
Just for fun, here are my stats on my Type 59. Better than most of my other tanks' stats sure... but revealing too.
Wins: 216 (50%)
Tanks destroyed: 304
Please note that I survived less than a third of my battles. If 59's were so hard to kill... well, that number would be a lot higher, right? Or maybe I just suck.
Anyway... quit worrying about the 59's and just track them so someone with a bigger gun or a better aim can destroy them. Rinse, repeat.