The flaw is more than the abuse.
The ratings work very well after the initial provisional BKR has been awarded, it is how the initial rating is derived that is often specious.

There is a big difference between inaccurate and wildly spurious.

Here is a real example from earlier this year. You can find many similar examples across all games.

Game 1 won, opponent BKR between 1500 – 1600
Game 2 won, opponent BKR between 1400 – 1500
Game 3 won, opponent BKR between 1700 – 1800
Game 4 won, opponent BKR between 1500 – 1600

So what initial provisional BKR should be awarded?
1600 – 1700 Largely inaccurate, as we have information on a 1700-1800 win.
1700 – 1800 Inaccurate, but best we can do with information available.
1800 - 1900 Largely inaccurate, no information to validate this.
1900 – 2000 Grossly inaccurate, absolutely nothing to suggest this.
2000 – 2100 Wildly Spurious!
What was awarded? A figure half way between 2000 – 2100.

You decide, flawed or not?