(re: Adventures That Might Have Been) Hmmm…..
Most of the series were still going when I left Sierra.
Manhunter ended because the Murrays left to do games for Broderbund. To the extent other series ended, it was because they didn’t sell well. For instance, Freddy Pharkus … it sold ok, but not well enough to keep it going. I’m sure I would have put another Space Quest game into development. Also Larry – and, of course a Kings Quest. Phantasmagoria was “killed” when Phantasmagoria 2 didn’t sell (Roberta wasn’t involved in the second game).
As to painful decisions to shut down a series: I can’t remember any – if there was a market for a game, I put it into development. If there wasn’t, the decision was easy.