are you referring to Superslab and Superslab Direct at Churchies?
If so, then yes, the first bolt is high. But… at about 4 m above the ground, that means that the climber’s feet are 2 m above the ground, which is quite flat, and as the slab is at about an 80 degree slope, the faller tends to slither down, not plummet. While there certainly is the potential for an injury, I’ve also injured myself (bad enough to stop climbing for a month) by tripping over a 1 cm high pebble. Where do you draw the line?
However I think that the main reason why the bolt is so high is that the climb was first done in 1980, that is back in the daze when the ethos was ‘The Leader Doesn’t Fall’ and ‘Bolts are a necessary evil’. Similarly with Bootiful next to it, where the first rusty piton is at about 6 m. I don’t do that climb. Similarly with a few others such as Inner Tension.
Now times have changed since the 1980s. If Superslab was done now, would it be bolted differently? Almost certainly ‘yes’.
So if you find it too scary, then don’t do it or get someone else to lead it. I’ve done it plenty of times and am happy doing it. But as I mentioned above, some of the other climbs I don’t do, either because they are crap or too scary.
As for belay bolts too close to the edge, yes, there are some in stupid places. But then the person setting up the belay should have something as a back-up. A good example is Striding Edge area at Statham’s, where the two bolts are about 20 cm from the edge. (There is also a bolt on a rock about 2 m from the edge, but that would probably go over the edge if you gave it a good shove.) I simply use these as back-ups and belay off other things – trees, other rocks 10 m behind etc.
If the belayer is knocked or falls over the edge, then they have not set up a safe belay, irrespective of the location of the bolts.