Do American airports treat overseas visitors badly on their first visits?

I hope I don't sound like I'm complaining or upset. I'm actually curious about the American view on overseas visitors.

On my first visit to America from Australia, when we arrived in LAX Airport, we were treated a bit badly - we had to stand waiting in an empty waiting room with others for 30 minutes, and even when they inspected our passports and before stamping them, they asked about how much money we had. When we replied that we had about $2000 in total, they almost didn't let us through anyway. It almost became an argument. Even when we were leaving USA, they inspected us as suspicious and looked through all our suitcases - which we didn't find out until after we arrived home.

But on the second visit to USA, we weren't treated like that. While the first time took an hour just to check out of the airport, the second time took about half an hour, and we were treated better - no asking about money or we were treated with suspicion.

Mum guesses because we're now frequent flyers to USA, we have a good record with them and the American airports now trust us.

Of course not.

That sounds like an average situation, not intended to be bad. Processing just take awhile.

In my experience, the security officers at American airports have no sense of humour which makes them come across as cold and officious. Most other countries I have visited, the staff are either reasonably neutral or friendly. It is just their way and once you know that, it shouldn't bother you too much. It isn't you - it is just the way, I presume, they are trained.

You may be a frequent flier to US, but I'd guess not a world traveller if you don't understand that most countries' immigration services will inquire into how you plan to fund your trip! Australia does it too. I've seen it asked hundreds of times on those fly on the wall documentaries about immigration services. You need to prove, especially on your first entry to a country, that you are a legitimate visitor, there for the purpose you stated.
I don't happen to find US immigration at all welcoming. It's very rough around the edges with not much thought given to courteousness, but, let's face it, landing stages in any country are its first line of defence against people who wish it ill, or want to take unfair advantage of it, so better a little bit unfriendly than careless. But I do think that track record can ease your journey through immigration if you have a decent one.

We're Americans. My husband flys over sea often for his job, he has for years.
Sometimes it take over an hour to get through customs, other times he walks right through. He was strip searched one time. He never was before or since.
This has nothing to do with not being an American.
They are not there to be friendly. They are there to do a job.
Spot check on your bags is just that. A spot check. They do it routinely. They check a random person's bag.

I don't know why you would have been put in a waiting room. That's not normal. Usually, everyone arriving on a plane walks together to immigration. Then there may be separate lines for those with US passports and those without. Visitors may be fingerprinted, but it doesn't take much more time to get through immigration, unless there's some problem with their visa. Then we all claim our luggage from the carousel and walk through customs. What you encountered was unusual, and unless there was something about your paperwork, I don't know why that happened.
Visitors from Mexico and Central America get more scrutiny because so many overstay their visas.

Usually no.
The wait line at Customs really depends on what other planes landed a few minutes before yours. If you are leading the herd or at the tail end makes a difference too in waiting time.
You make a 30 minute seem like weeks.
Welcome to the real world. Visitors to Australia wait that long too.
I have had waits of less than 20 minutes and over two hours at the same Airport. Just the way it is.
Reason you do not plan on fast clearance if you have a connecting flight afterwards.
Over the Ocean flights can easily be an hour late or early from their scheduled time to be at the Customs inspection area.
Just takes one two flights out of order to jam up the process for many other on time ones.

Is keeping international travelers in a staging area for 30 minutes unusual for any country? No.
Is asking asking to see your passports? Obviously, not
Is saying that you have $2000 cash? NO! So I don't know why you think this almost started an argument. Was the customs agent concerned you didn't have enough money for a holiday in California?

Oh no, your bag was inspected and the Custom agents put a note in the bag saying what happened. Don't check bags in the USA if you don't want this to happen. This is standard protocol on domestic and international flights. Please don't think you were special because this happened to you. Every flight will have some bags that are checked.

Mom is incorrect. Customs processes are changed all the time. Sometimes are more busy that others.
Do you think it is different for US Citizens arriving in Australia? It's not.

No. Try Canada next time, they really know how to pi$$ you off.

No worse than I'm treated every time I go to a foreign country.
And I travel internationally at least once a year