Troy: Why not on the tour?

Maybe you should ask the RS tour office.

I suspect because it's not near the other sites they want to visit. I have been and I wouldn't go to Turkey and not see Troy, although as you probably know, there's not a lot left to see there.

I did visit Troy on a Gate 1 tour of Turkey. In terms of interesting archaeological sites in Turkey, it scored fairly low on what a visitor could actually see. It was interesting to view the several different layers of city, but the site itself was not excavated with care originally ( foreign treasure seekers) and it impacts the experience. The most worthwhile display on Troy is actually found in Istanbul at the Archaeological Museum.

Just like when you plan your own trip, tour planners have to prioritize what attractions to include and what, regrettably, to skip. If I remember correctly, the RS tour ends in Izmir and does not go that far north.

There is nothing to keep tour members from continuing on to Troy after the tour.