>traffic, parking, what if the new people are different from me

those all seem perfectly reasonable

And all perfectly addressable. YIMBY policies typically addresses housing first, but also understands that parking/traffic issues also happen when cities grow in size. The NIMBY point that "these things are bad and will only get worse!" presumes that there's not changes made to address those as well (increased public transit, bike initiatives, parking garages).

That said, if your issue is strictly xenophobic/culture shift, sorry but you can't legislate demographics (and maintain a moral high ground). The idea that new people will have a higher rate of criminal behavior, this can again be addressed with deterrents towards criminal behavior rather than deterrents towards population growth (which isn't going to be stopped, just exploited using by those in control of the current housing supply)

>you can't legislate demographics (and maintain a moral high ground)

You can indirectly, and you don't need to have a moral high ground. I wouldn't care about that, I would only care about my wellbeing, the wellbeing of my family, and the price of my house.

Not really. Your right to an unchanging neighborhood absolutely does not eclipse the right of a long-term renter's ability to stay in their community, or the right of a newcomer's desire to move to a better job. Plus, climate change. Sprawl and traffic are bad for the planet. California will never be able to meet its CO2 reduction targets if it does not discourage more driving, which we can only do by shortening the distances between where people live and where they work, and compressing the areas people live in.

"Your right to an unchanging neighborhood absolutely does not eclipse the right of a long-term renter's ability to stay in their community, or the right of a newcomer's desire to move to a better job"

Aren't the tech newcomers the ones that are threatening the long-term renters more?

The connection between NIMBYs and displacement goes like this: newcomers come in and increase prices of rentals, NIMBY homeowners refuse to build more housing, long-time renters are displaced by the newcomers who can afford more. Simple supply and demand.

Tech is certainly part of the problem, but California has been underbuilding for the past 30 years. This problem goes way back, and it was made much worse by Reagan's massive cuts to HUD back in the 80s.

not at the cost of decent housing options for people across a broad range of lower/middle incomes and also not accommodating baseline population growth regionally.