If anything it comes down to two things:
1. Public image of the company, for example the use of women was heavily criticised by groups, over the top violence and so on. The Benoit thing was merely a small thing in a long list used against the company, all that did was highlight the danger of overdoing crazy amount of blows to the head. A lot of things that the WWE did whilst not PG rated were not needed (the sex references, Mae Young, the over use of swearing etc) Take those away and really chances are it would have been rated PG.
2. The most important one and the one the Attitude Era fans can't accept, the audience changed. 40% of the WWE audience is now women and children, sure you can point out the 60% but who spends the money? Women and children buy the shirts, buy the PPVs, attend the shows the small percentage of that 60% don't buy the shirts, watch PPVs for free and criticise the show for everything. The product now is more catered for the balance of the entire audience, I see no difference than how it was done in the 80's and much of the 90s. The WWE is building for the future now, it can't be stuck in the past and its 'glory days', it needs to move on and appeal to the current audience. Its how it has survived and whilst it took its time in the 90's to evolve when it did catch it, it played a part in the death of WCW (although most of it was WCW killing itself)
At the end of the day, ask yourself this? Since Raw turning PG (seeing Smackdown has always been PG) what has actually changed in the product?.... Lack of swearing? big deal, Sex references? I think you are watching the wrong show for this, Comic characters?.... Hang on there as there has always been comic characters. Point being PG has done very little to the actual program, don't confuse bad writing/booking with what the show is rated.
As said before, Benoit's death and the incident leading to it changed very little in terms of the product. Benoit's death led to a ban in chair shots to the head (after the investigation showed the link), which I believe even Dixie Carter agrees with, the improvement of the wellness program and exposing a few home truths. Things like stopping the match for blood comes down from many factors not related to Benoit, just look at Undertaker/Orton Snr and what could have happened there is just one example.