I have never been bitten by a mosquito anywhere along the coast near the ocean and certainly not in any of the dryer/desert areas. I've spent a lot of time in the Mojave and other parts of SoCal, it's far too dry. Rattlesnake bites while hiking are a far greater concern of mine than mosquito bites, there are simply _zero_ mosquitoes in my daily life, it's a complete non-issue.
The midwest is where I grew up, so I know what it means to have the outdoors made hostile by mosquitoes. It was relatively trivial to move to greener pastures, and I'm glad to have found absence of mosquitoes was one of the rewards.
I react awfully to mosquito bites, and absolutely detest them and it's a big part of what keeps me from visiting home now that I prefer to spend so much time outdoors.
The simple fact is there are pros to California's perma-drought condition.
And also "it's a big part of what keeps me from visiting home now".
Surely you see how maybe some people would like to visit home, etc.
Also displayed in this thread, there are people ignorant of the possibility of simply moving somewhere no mosquitoes exist - operating under the assumption that it's unavoidable. Indeed, prior to my leaving the midwest, I had no idea there were places people could enjoy nights being active outside year-round without insect bites.
Obviously everyone is going to have different priorities, for many mosquitoes are a minor inconvenience sufficiently mitigated with bug spray and candles. I assume those people wouldn't be willing to move to escape them, but I presume they also wouldn't be vehemently raging about extincting the species as a priority.
I'm here to tell you - yes, you can move to such places, and it's not even particularly difficult or costly. There's _plenty_ of incredibly affordable desert land in California, where there are effectively no mosquitoes. If moving is too inconvenient for you, buy a recreational desert property and vacation there! It's that cheap. The fall-winter climate is ideal and remains good into the spring, there's no humidity, and of course - no mosquitoes!
Or don't make any changes in your life, and fill yourself with rage about the environment you find yourself in, as if that's going to help.
Maybe your diet/genetics/clothing choices are just not as attractive to the mosquitoes in your area - I've seen huge differences in mosquito attention between individuals within a group.
It's also typical that reaction to mosquito bites decreases with age after adolescence (https://www.ncbi.nlm.nih.gov/pubmed/2571626) so maybe you moved as your reaction to mosquito bites disappeared (and maybe you can visit home again).
The last time I experienced mosquitoes in California was camping in a rainforest. I am not immune or unattractive to them, they are quite attracted to me.
But I'm also not putting myself in residential areas that would be desert if not for the constant irrigation. You're certainly able to find places with mosquitoes if you're looking for them - why would you do that if you're averse to them?