Cops are also allowed to keep guns after they retire. It's important to remember that guns are issued to police for self-defence, since the work they undertake puts them in harm's way. That doesn't change after they retire.
That no one else has that right maybe tells us we should expand CCW reciprocity. It's already something like 35 states.
I'd need to see some stats on how often retited police officers are retaliated against by criminals before I'll buy that this is anywhere near likely enough to worry about.
How many retired law enforcement officers go on binge shooting sprees?
Or should we oppose them having a legally purchased firearm just because?
The double standard!
Either way assuming that being armed doesn't provide a 100% effective deterrent, statistics should still help us here. Even assuming a very high deterrence rate, you would still expect to see at least a handful of revenge murders of retired cops every year if this was a significant problem at all.
>provides no defense advantage should they do so
This one should be very easy to determine. How many times each year do armed retired cops thwart revenge attacks?
From what a quick Google search tells me both of these things basically never happen.
If not, how are these police privileges remotely relevant to any need beyond that of a normal citizen?
First of all, why are they not bound by the same magazine capacity limits? If more than 10 rounds are needed for self defense, shouldn't everyone in the state have that tool at their disposal (per Heller)?
Similar question about buying a newer model of pistol. Why would the 2019 model be crucial to keep a retired cop from getting gunned down, but forbidden to others? There isn't even a major functional difference between a 2013 glock and a 2019 glock.
And generalizations about how retired police somehow need their special guns and nobody else does are just not compatible with the notion of individual rights. I bet a lot of abused women are in much greater danger than an average retired cop. Who decides who the special groups are that get special privileges?
Fundamentally, a police officer is a citizen. It happens that their job is dangerous, and I respect and admire their courage. But it's also a position of power, and we need to keep that under some control so that we maintain trust. Arbitrary privileges erode that trust.
It's not about keeping people safer, nor about making it easier to track criminals...
It would be less offensive to just be transparent about these regulations. It's about making it more difficult for anyone to legally purchase or maintain a firearm.
The argument you make about Gen 3 vs Gen 5 Glocks actually suggests there is no reason to restrict the general public from buying them, either. The Gen 5 has duplicate controls for left-handed shooting and is thus safer for some people.
All the points you are making are basically why the laws are dumb -- 10 round magazines are not significantly safer for the public than 17 round magazines, for example -- and no one likes to be subject to useless restrictions. Least of all cops.
But now, Western governments have to endure usurious prices or massive budget/time overruns for basic supplies (e.g. Germany has a problem with shoes for soldiers), quality issues (in Germany, G36 rifle, police uniforms in Bavaria and IIRC there were also issues with protection vests).
Planned economy Soviet-style didn't fail because of being what it was, it failed because of a lack of data gathering and processing (demand modeling), as well as the procedural inflexibility to react to short term changes.