I think there’s a lot to unpack from the OP, some of which is probably more suited to IMHO, rather than Factual questions, but the answer tot he direct question is probably ‘no’. Keep in mind, that police officers, who have a job requiring sufficient accuracy to qualify, rarely practice beyond the minimums to do so.
-If- those estimates are correct and represent the mean, 15 hours of practice a year is certainly not going to build amazing accuracy, which is secondary to the numbers below:
Being shot at is STRESSFUL. Your accuracy when the other party is returning fire is going to be, shall we say, subpar.
Gangsters and thugs probably spend less time shooting for accuracy, which is one of the reasons that fully automatic weapons are popular, with the theory that you can spray and pray. Which, from what we see in too numerous drive-by news stories to mention, is false. Sure, you’re putting a lot of people at risk in the area, possibly but not particularly the target.
Briefly regarding the point on self defense - when I got my training, they very firmly pointed out both the physical and the mental aspects of a defensive shooting. If you aren’t physically practiced enough to get a firearm out under stress, remember to remove safety and chamber (depending on firearm), and wait until you had the target properly sited, then you were a danger to others. They said that a minimum of a hour of live fire a month should be expected - and that was leaving out the concerns that whether you’d be able to emotionally handle the situation (not freeze) or make yourself pull the trigger knowing you were going to kill someone (because if you were planning to ‘stop’ or ‘wound’ someone you were again, a danger to self and others).
Considering the emotional aspect above, outside of individuals with greatly reduced affect, this may be a pro rather than a con for drive-bys: you’re shooting up a dirty rat but not making eye contact or having to visual confirm what you’ve done. But that’s firmly IMHO.
Incidentally, I’m sure there are plenty of exceptions to the general rule - thugs or gangers who do take the time to practice - for fun, for accuracy, or just for looking cool. Just that they’re probably the exception, not the rule. Cops train to use firearms in defense of self and others, gangers/thugs train (if they do) to use on people unlikely to resist under threat, or against others of similar untrained background.