Comparing apples to oranges. A bolt snap needs to be detached, creating the possibility that the item will be lost while the diver is manipulating it. This unless you use a segment of line to connect the bolt snap to the item, which in turn creates the risk of entanglement on its own, as the item dangles from the D ring. Retractor does not need to be detached to use.
I suppose that's fair - if you're a cack-handed, klutzy, Mr Bean-type diver.
In 20 years of diving, I've never 'dropped' anything. I unclip, utilise, when not using re-clip securely. Stuff that's in my hand... that I am using, I do not drop.
That's a crafty skill that I developed over many years on dry land - it works just as well in the water. It even works for me when very task-loaded... such as filming video during technical shipwreck penetrations, whilst working with guideline in low vis on sidemount... I'm assuming any reasonably coordinated diver could manage the function of "holding, not dropping" an item on an OW dive...
Of course... you cannot 'drop and lose' an SPG. So there's no valid reason for a bolt-snap there. With anything else, at most, out a wrist lanyard on. When you want to use something, open your pocket, fit the wrist lanyward, unclip the bolt-snap....
then use it without fear of mal-coordination costing you money.
One serious tip... for those genuinely worried about a 'klutz' moment is to simple wear a 'bracelet' of bungee cord. Unclip the item's boltsnap from storage, re-clip that bolt-snap to the bracelet, whilst you hold it. Now it's secure, easier to hold.... and you don't look like Elton John's Christmas Tree in the water...
I found a camera once... it had a lovely retractor on it. Didn't work out so foolproof for someone..... I threw the retractor away, put it on a bolt-snap... still using it 7 years later
Afterdark - that's a fair point. Arthritis could cause problems... first solution would be bigger bolt-snaps, I suppose. I've got a slightly disabled right hand from an old accident - it gets achy/tired quickly. I don't have problems with manipulation yet - but it's something I anticipate over the coming decades. To be honest, my primary considerations would be issues like LPI or OPV manipulation... followed by shut-downs etc..