It seems to be a trait of expensive, high production/high cost type shows. It also may be necessary to do that in order to keep the cast together. I don't mind waiting as long as they keep the quality level the same. With ST, I guess we did Christmas, Halloween, and now Summer Break.....interesting. Season one was just so damn good. I loved binge watching it again prior to season 2. I loved season 2 as well - can't wait to watch it again. Might be good to do that now since it is Halloween season.
I think the talent both in front of and behind the camera likes it as well, because it gives them more time to work on other projects (or not).
It's also highly dependent on the platform these shows air on. Traditional OTA networks are completely beholden to their advertisers and they are basically slaves to the Neilson ratings. They could
never afford to take an established show off the air for a year. Basic cable is partially reliant on advertisers, but they also earn their money from carriage fees. So they have a bit more flexibility. But HBO and Netflix can do whatever they want, as long as the subscriber base stays high.