There are bio-ethicists arguing that it's wrong to eradicate an entire species. There are also biologists expressing concern about damaging the food chain.
Regarding the former concern, it's only a tiny segment of our world that actually cares whether mosquitoes exist or not as part of some abstract idealism or wishing to preserve biodiversity. Most of us would be beyond happy to see this miserable creature eradicated.
Regarding the food chain, there are some 5,000 species of mosquitoes, of which only about 100 feed on mammalian blood. Out of those 100, nine species carry disease such as malaria and zika. If we only targeted those 9, we'd have a huge win while scarcely affecting the pollination and prey species role of the rest of the family of mosquitoes.
If we targeted the 100, we'd greatly increase the quality of life for not only 7 billion humans but also for tens of millions of mammals made miserable by blood sucking swarms. The great herds of reindeer of northern Canada, for example, deliberately run in single file, to reduce exposure to mosquitoes that swarm around them in the spring. Mosquitoes are a serious parasite up there; one herd animal can lose a pint or more of blood in a single day.
A few years ago someone might say kill all bees kids are dying. We know better now.
I don't feel like reductive arguments are useful for incredibly complex systems.
[0] https://en.wikipedia.org/wiki/RTS,S
[1] https://en.wikipedia.org/wiki/Mosquito_net#Insecticide-treat...
[2] https://ourworldindata.org/malaria#bed-nets
[3] https://ourworldindata.org/grapher/malaria-deaths-by-age
Caution is in order.
It is inconceivable to me how eradicating the malaria parasite by eradicating a few of the thousands of species of mosquitoes could end up killing hundreds of thousands of people every day. The much more likely scenario is that doing nothing allows the malaria parasite to evolve into something much more deadly (and that is pretty unlikely, given how long malaria has been around).
Care to spell out the "100,000 people a day dying" scenario?
Do you believe in evolution? The children who live are more likely to have anti-malaria related genes and so will there kids.
Would you save 250,000 children today just to condemned millions in the future as populations increase and more children as exposed and side effects are discovered.
I would probably save 250,000 kids today but tomorrow when millions more are at risk I will wish I thought longterm.
There are over 250,000 children under the age of 5 that die every year from malaria. In my ethical system, there is very little that can possibly justify trying to prevent something that will save the lives of 250,000 children a year. Anyone who actively tries to delay wiping out malaria causing mosquitoes is classified with climate change deniers and anti-vaxxers.