i have to agree with GM4Him, having hordes of enemies isn't simply a "making the game longer". WotR has tons of issues, ironically them trying to mimic tabletop rules of an insanely crunchy system TOO much, but the number of enemies doesn't feel like it's simply thrown in there because they couldn't think of anything else.
Also, the idea that video game devs just make more enemies because it makes the game longer is bizarre. Zombie horde games entire premise is that there's a HORDE attacking you. Another game that I love is the Earth Defense Force series, which centers around a ridiculous amount of monsters/aliens that a small group of soldiers is fighting. The whole point is that it's so overwhelming, there's no possible way to win, but somehow, humanity finds a way. Thematic reasons for the number of enemies isn't "finding meaning where there is none", that's a very common story telling tactic.
