My initial reaction was no, but upon reflection, yes. If:
A) It is a multiplayer-only game, a la TF2, in which case awful single-player can't be a deal-breaker, it's not even a factor. Games like this can still certainly be fun. If you're into single-player, this simply isn't your market.
B) It is clearly a multiplayer-centered game, a la Halo, and the the campaign is optional; in such a case it's similar to a tutorial, getting the player familiar with the game before throwing them into the competitive arena. This is fine; but must still include split-screen, because not everyone has an internet connection.
It is inexcusable, though, if the game is single-player only, or if the game was single-player only, but the single-player dropped in quality after the introduction of multiplayer. This would be inexcusable.
A) It is a multiplayer-only game, a la TF2, in which case awful single-player can't be a deal-breaker, it's not even a factor. Games like this can still certainly be fun. If you're into single-player, this simply isn't your market.
B) It is clearly a multiplayer-centered game, a la Halo, and the the campaign is optional; in such a case it's similar to a tutorial, getting the player familiar with the game before throwing them into the competitive arena. This is fine; but must still include split-screen, because not everyone has an internet connection.
It is inexcusable, though, if the game is single-player only, or if the game was single-player only, but the single-player dropped in quality after the introduction of multiplayer. This would be inexcusable.