Fighting Mosquitoes With Genetically Modified Mosquitoes

You don't get it, do you.
DDT kills some mosquitos... and also other insects, alternative pollinators of those plants you're worrying about. And every bird and rodent and reptile that eats the poisoned insects. And every predator that eats those small animals. And so on. The poison doesn't affect the food chain in hypothetical ways as you describe (and which might never come to pass: some other insect which was competing for the same pollen will breed like crazy, the birds will eat it, equilibrium restored), it's proven to be directly deadly.

And I don't have to tell you what happens if a swamp is drained... that's a habitat and all its denizens, gone.

So yeah, the methods used today are far more destructive of the environment.
The one in the OP is actually an improvement.

Difference between that and this THIS HAS THE ABILITY TO SPREAD. NOT LOCALIZE IN A SINGLE AREA. Poison only affects the immediate area then animals that eat it tend to die before they are ably to make it a long distance. This however is genetic meaning as long as a single mutated male remains this wont go away and wont be able to be stopped.

Your example is a bad thing that's happening but we have some control to stop. This once introduced cannot be stopped this is the worst situation.

just so you know some plants only have one type of incest to pollinate them most flowers adapt to attract certain bugs to pollinate them an example would be a yellow flower attracting a bee the yellow color is what cause the bee to go to it.

@alloy yes you have it spot on. It's a little thing we like to call symbiosis.