I am honestly saddened by the fact that it has come to this. What *is* the horde night? An event that spawns a bunch of zombies which you farm if you feel like it? Well, unfortunately, that's exactly what it is. It is optional. And since it's optional, people feel like they need incentives to participate, else there is no point to it and as you said "it's a waste". One of the reasons why people also complained about decreased loot.
I wonder if TFP envisioned it like that or just were misguided by the "allowing people to do anything they want" crowd, which later also complains about the game becoming arcade-y, boring, grindy etc. But more importantly, If we want to put the tower defense elements to good use, the horde should be something which you have to defend against. Defending yourself and your base is the best incentive. Hopefully, when the speed bug is fixed, barricading will become a must with the nightmare speed setting.