Is there a point where safety and enjoyment of the experience reach a point of diminished return of enjoyment because of the emphasis on safety.
Yes... but...
As we can easily see just by looking at the situation (or perusing this thread, if we're in a rush), there is no set tipping point where enjoyment starts to go downhill for every person. For some of us, just enough safety to make survival likely is the limit. For others, only when safety is taken to ridiculous levels does it become meddlesome.
I did some quick illustrations to show a few personality types. The vertical axis of the graphs is "enjoyment", while the horizontal axis is "safety". These are just qualitative examples, of course. Real people tend to be more complex than such simple two-dimensional text art. Anyway...
[C]|....................
|____________________
|....................
|....................
|....................
|....................
|....................
+--------------------
"Oblivious"[/C]
This first response curve is most commonly seen in some new poorly-trained OW divers. They are oblivious to the dangers involved in diving, and so, their enjoyment is basically constant across all values of safety. Being new, their enjoyment level is natually high.
[C]|....................
|...____.............
|../....\............
|./......\__.........
|/..........\__......
|..............\__...
|.................\__
+--------------------
"Normal"[/C]
A "normal" person starts out with a moderate level of enjoyment (tempered somewhat by the unease a lack of adequate perceived safety might cause). Adding a little safety quickly brings them to a plateau, where any small increases or decreases in safety make negligible difference to their enjoyment. When more safety is added, however, it eventually becomes cumbersome (too much gear, too many procedures,
et cetera), and their enjoyment diminishes.
[C]|\...................
|.\..................
|..\.................
|...\................
|....\...............
|.....\..............
|......\_____________
+--------------------
"Reckless Adrenaline Junkie"[/C]
A reckless adrenaline junkie starts off with extremely high enjoyment levels, but any added safety measures quickly get in the way of the rush. A level of safety that a "normal" person might appreciate could be immensely unpalatable to them. (This response curve is not usually found in its pure form, but is often blended with other response curves in real people.)
[C]|...........___......
|........._/...\.....
|......._/......\....
|....._/.........\...
|..._/............\..
|._/...............\.
|/..................\
+--------------------
"Safety Conscious"[/C]
A "safety conscious" person finds little enjoyment without safety. At the safety level at which a "normal" person's enjoyment plateaus, this person's enjoyment level is still increasing. By the point in safety at which this person's enjoyment level peaks, even a normal person may find things burdensome.
The "safety conscious" diver might be perfectly happy carrying redundant *everything* (pony or doubles, two or three lights, two or three cutting tools, drysuit or lift bag, two masks, and so on), while the "normal" diver might think that's crazy and simply be wondering whether to go with an integrated octoflator. The "reckless adrenaline junkie", meanwhile, might be upset by a boat requiring an SPG, and the "oblivious" divers... well... someone might want to remind them to put their fins on before that giant stride, but they do seem to enjoy themselves.