I'm of the middle ground when it comes to conservation. There's a certain line where a species is either doing fine and we personally fucked everything up for it one way or another, or a species is already so pathetically outclassed on a natural level that they deserve to be allowed to be wiped out provided they aren't a cornerstone species that's essential to the environment they inhabit. I'll give an give an example of each category, and to make it spicier have them both be cute critters that pull on humanity's fragile heartstrings.
Sea otters. These little guys were nearly exterminated because we found their pelts oh-so-valuable. In other words we killed them off for an unnecessary luxury (such fur would only go to the elite and not people who needed fur to survive, at least when their population REALLY started to take a dive). But as a consequence, their very biome, kelp forests, suffered heavily from their removal as they had kept sea urchins, who can fell kelp in vast qualities like overzealous beavers, in check. Which in turn was disastrous for countless other species who called such forests their home. In areas where the otters have bounced back, once barren no man's lands have become bountiful, productive forests once more.
Giant pandas. These lazy fucks nearly died out from little else but their own incompetence. They eat bamboo, and only bamboo, which to add is an extremely nutritiously poor food source, doubly so for an animal with the digestive system of a carnivore. And guess what bamboo tends to do? All flower at once every several decades and then die. These dumb animals based their entire livelihood on a food source that can just disappear in a moment. What's more, they don't offer any ecological advantage like sea otters do. They could disappear and life would be no different for other species. To top it all off, they're so damn finicky and pathetic we literally had to force them to fuck to get their numbers back up. All in all, they only still exist because they just happen to pander to our stupid cuteness factor bias. If they were an insect, salamander, plant, or other such far more unpopular species, they would've rightfully died off a long time ago.
Bottom line is, even after you discount mankind's stake in the world there will always be species that just flat out fail in this sick and twisted game we call life regardless of what we're doing. It's but the natural cycle that they're phased out by something that does the job of survival better, and we're just wasting time and money trying to keep them alive for the sake of our precious sensibilities.
