As the targets become longer, especially on the advanced courses in Travelers turf, the unequalled ultra long sighting plane of the gas gun becomes more attractive. As shooters become more sophisticated, they start to look for little ways to improve their gun fit. The auto's stock can be shimmed around at will with just a screw driver and a couple of pieces of plastic. It can be made to fit absolutely perfectly with no compromise. It is easy to readjust it to account for changes in the shooter's weight or shooting style.
Some gas guns are much more reliable now.
While the Remingtons have some problems, the Berettas do not. The Technoid's Beretta 303 is approaching 30,000 rounds with no broken parts. When the gas gun does go down, it can be repaired with a few simple tools and inexpensive spare parts. Field repairs are out of the question. A final reason for the resurgence of the gas gun may be that many shooters have tried all the other guns and this is the only one left to try before they have to start blaming themselves.