Yes, you want to keep a viable population because they may be a gene modification delivery system. In warm countries, it is the cheapest and broadest way to "infect" a population. If you do find a way to do RNA insertions from injectables, this would be an ideal system.
Perhaps that is why we have them. My friends had a similar discussion on HIV a long time ago, that it may turn out to be the ultimate cellular insertion tool we ever come across. As i recall, if you have HIVb, you body doesn't develop AIDS, so a de-weaponized HIV virus may become a tool down the line. The same may be said about malaria and the other apicomplexans. They have little organs at the front of the parasite that allow them to easily slide into cells, videos make em look like they just swim up to a cell, and nose into it. Pretty amazing biology
So another reason to exterminate "wild" mosquitoes is that otherwise they are a convenient vector for bio-terrorism.
“In 2015, there were roughly 214 million malaria cases and an estimated 438 000 malaria deaths.” While we don’t know how many humans malaria has killed, an estimate of half of everyone who has ever died isn’t absurd. Because few people in rich countries get malaria, pharmaceutical companies put relatively few resources into combating it.
The best way to eliminate malaria is probably to use gene drives to completely eradicate the species of mosquitoes that bite humans, but until recently rich countries haven’t been motivated to such xenocide. The Zika virus, which is in mosquitoes in the United States, provides effective altruists with an opportunity to advocate for exterminating all species of mosquitoes that spread disease to humans because the horrifying and disgusting pictures of babies with Zika might make the American public receptive to our arguments. A leading short-term goal of effective altruists, I propose, should be advocating for mosquito eradication in the short window before rich people get acclimated to pictures of Zika babies.
Personally, I have (unsuccessfully) pitched articles on mosquito eradication to two magazines and (with a bit more success) emailed someone who knows someone who knows someone in the Trump campaign to attempt to get the candidate to come out in favor of mosquito eradication. What have you done? Given the enormous harm mosquitoes inflict on mankind, doing just a little (such as writing a blog post) could have a high expected payoff.