The consequences of killing birds and insects could be worse than the cost of keeping them around. That's what it boils down to. Knowing that, you just have to

The consequences of killing birds and insects could be worse than the cost of keeping them around. That's what it boils down to. Knowing that, you just have to figure out if you think this is true for the things you value. You can try to figure this out yourself, or, if you think someone else could make a better judgement, see what they think. If the answer is "yes, perhaps the consequences of killing birds and insects could be worse than the cost of keeping them around for the things I value", then you should care.