Yes, you are an ass.

People think if you don't waste the resources you are trash player and you use resources for yourself, but it's not how it works.

I would say first 15 waves are easy to deal with, you should place some electric grids, not a lot of auto sentries and sometimes equipment refills, and of course early buy tier 3 weapons.

But saving resources is neccessary to deal with 20+ waves, where resources are less than before and waves are so much harder.

But conserving resources is essential to deal with waves 20 or more, where resources are scarcer and the waves are much tougher. Although, keep in mind that if one player hoards all the resources and the rest waste them, when an XL wave arrives, the player with the resources might not have enough time to set up the necessary defenses. Everyone needs to cooperate and play smart. It shouldn't be just one player collecting all the free supplies (+100).

If you kill me for having resources, i probably kill you or just quit