I think this evaluation is justified! I have been playing this game since many years on an "occasional" pattern and I find the games have been more interesting of old. As for 2.6 I have a savegame here which, when I take over the most advanced AI player, shows they built 28 Workers for 10 cities and these workers are standing around, nominally building roads but not building anything, while most of the economy fields are still lacking irrigation. AI always shows tendencies for the extreme and runs itself into non-working extremes. Actually, the mentioned bug could also be a game-playing bug, which then is even more serious.
Unfortunately, I see this program on the degeneration course. Whether this dangerous drift can be reversed is an open question!