That is 1 video, as someone who watches streams and plays daily it isn't any worse then it's been in WOL and in HOS. 

HOTS era had the broken infestor/Broodlord builds. The scene atm is better, even Terran has had recent buffs. Only argument you can have is that Terran has been at a disadvantage since HOS, but the current best player in the world plays Terran.

That's one video of many, other streamers like Pig, Vibe, Ruff, Protech have ran into such individuals on stream while some players have live streamed to hacks to bring it to Blizzard's attention unfortunately they can't ban these cheating clowns from the ladder because they stupidly made the game's multiplayer f2p.

Broodlord Infestor wasn't a problem in HOTS in fact the Infestor was a dead unit in HOTS you're thinking of WOL which is almost a decade ago, the current best player in the world plays Zerg in Serral as he's had the strongest record so far but either way the problems aren't just with one race it's with all of them and the 12 worker start. The game is in a terrible state and is frustrating for people on the ladder to play.

The current best player is Maru not Serral, he won WESG and the two GSL's so far. The races don't have problems, and the 12 worker start simplified openings which helps balance. 

Serral beat all the top Korean players in his wins including Innovation and Stats, Maru in the same recent tournament got destroyed by someone Serral swatted.

No 12 worker star broke the game it's is the main cause of the erratic early game the game has and I can highlight why, 12 workers gives players near full mineral saturation the result is builds that were never intended to be viable now exist and example is how Protoss can expand as fast as Zerg now while being able to pressure your natural with an array of cheeses and pushes. This was not possible before because the 6 worker start meant taking a gas impacted expanding and a players economy this what everyone on BNet, TL and Reddit SC are now realising and bringing up because you can't balance a game where the flawed econ undermines its fundamentals.

And where do people bring this up? I see no threads of this anywhere.
You are very angry about SC2 for some reason.

While Serral has won GSL vs the World it doesn't automatically give him the title of best player in the world. Maru didn't get destroyed by Stats and Stats didn't get swatted by Serrel. Were you even watching the games? The finals was damn close.

In regards to the 12 worker start I haven't seen anyone complain about it recently. All complaints were when it was implemented which was almost 3 years ago.
And the game is now in the best state it has ever been. Games rarely are a build order wins. The matches are dynamic and fluid with lots of oppurtunities to outplay your opponent.
Not the goddamn snorefest that was HotS or the shitty one dimensional matchups of WoL. And the community as a whole agrees that its better then ever.

Even the hacker situation is nowadays way better then before LotV. Back than when HotS was out there were a lot of free hacks and many hackers on the ladders. Nowadays you have to play a insane amount of games to actually meet one. The TL thread of suspected hackers is mostly dead nowadays. And Blizzard makes hacks unusable on a regular basis so the only available ones you have to pay quite a sum of money for.

I would like to know where you get your information? I haven't seen a person beeing this angry at SC2s current state in a long time.