Where I want the designers to do exactly this - to find and fix the broken bits - and then hand it over to playtesters* whose specific mandate is "Break this game if you can". Lather rinse repeat until the playtesters can't find anything more to break.
Why? Because it's a game; which means (if they're doing it right) players will always be looking for an edge.
* - ideally selected from the hard-core char-op crowd.
No matter how many times you lather and repeat, 20 people won't find the errors that 50 people will. And 50 people won't find the errors that 100 people will. And when you release a product to tens of thousands of people.... A new error will always pop up.
Half the big things people complaining about either require tortured readings of RAW that are non-obvious if you are working from a reasonable RAI, or likely are not errors in the first place. A big thing right now is that Giant Insect allows for a web shot that reduces a creature's speed to zero. Many people are declaring this broken, unintended, sloppy and terrible! But... It sounds pretty much exactly like what a ranged spider-web attack SHOULD do. And yes, it could have had a saving throw, but then you need to hit and save, which is more dice rolling and just makes it less effective in the 90% of use cases.
Or to give a different example. Many people have said that Hunter's Mark requiring concentration was a terrible blow to the Ranger, because who would want such a mediocre spell at high levels? But, now we are starting to get a clearer picture, and the Hunter Ranger who Dual-wields at level 5 could very easily end up in the following scenario:
Cast Hunter's Mark as a Bonus action.
Attack three times with Light Nick weapons for a total of 6d6+1d8+12 or 37.5 damage
Next turn attack four times with same weapons for a total of 8d6+1d8+16 or 48.5 damage.
That could very easily end up as higher damage output than most other martials over that period. I mean, a level 11 Paladin using 1st level Divine Smites with Greatsword and GWM is getting 4d6+2d8+2d8+8+8 or 48. So with 1 turn of set up, a Ranger is dealing the same damage as a smiting paladin double their level.
So.... was it bad design, sloppy and ill-thought out? Or intentional design. Somethings appear to be errors, those are unfortuanate, but it gets increasingly difficult to untangle the lingering disdain for WoTC, disagreements in play style, honest mistakes that stem from expectations, and mistakes that are actually problems.