Safely? Absolutely agree. But it all depends on the circumstance. 80 km/h next to one park can be safe and 40 km/h can be unsafe next to another.
Well no it depends on the speed limit
You are basically saying to disregard the limit just because you deem it safe to go a certain speed.
I think you would be surprised. On my parents' street, there's a park next the which the posted speed limit was changed to 30km/h about 2 years ago. That hasn't reduced the average driving speed of about 55-70km/h, because it's a long straight road with plenty of visibility, and rarely is there anyone in the park or on the street. However, during the times where it is populated, people will slow down consequently; down to even 20 km/h, depending on where the people/kids are. They did this before the it was dropped to 30.
Of course, you can guess that the days they park cop cars next to parks are the days they know people will drive quicker; where there isn't even a cat (pas un chat).