I probably wouldn't get too worked up over having one talkgroup encrypted. There is always the possibility of systems going encrypted, although it is expensive and unlikely to become a widespread phenomenon.
I rememeber seeing on the radioreference home page an entire county... i think Hall county, that went to 100% encryption. I really don't see the point personally, even in the roughest parts of saint louis and even east st louis, they don't use encryption, and i guarantee there are more seasoned thugs there than there are in hall county BFE.
encryption definetely sucks, i will give you that, but i wouldn't jump out of the hobby over something like that.
Also, unless you know someone on the force, i would advise against asking. Officers love to play dumb about things like that because they are happier not telling just any random person on the street about something so critical as their radio. It may sound a little ridiculous to your normal person, but cops have their own circle of trust, and unfortunately your average citizen doesn't fall into it. You'll find that... or the rest of the cops who just don't know a thing about radios anyway.