today we'd like to give these jobs to really expensive machines instead of people
The machines are capable of working 24/7/365 (minus the maintanance hours) for no pay. In the long run, the reason menial jobs are being replaced by machines is that in many cases the machines are capable of doing the same job with far less cost per hour, and in the end that's what matters, not how much the machine costs out front.
right at the moment when jobs for people are disappearing
Jobs for people aren't disappearing, they're changing. The demand for low-skill physical labor has been going steadily down since the 1700s because as I already said: if you can do the job with a machine, chances are it's going to be cheaper and faster in the long run. At the same time as many jobs have disappeared, new ones have emerged and keep emerging.
we'd rather interact with machines, because you don't have to say "Thank You" to a machine.
Thank you has nothing to do with it. The two possible scenarios for me to charge my local travel card (ie. train ticket) here in Helsinki are as follows:
1) Go to a kiosk or a store, wait in line, hand the card to the person and state the amount of money/time I want entered, wait for the person to do that, then pay and take the card
2) go to an ticket vending machine, put the card in, press literally 4 buttons to renew my last purchase (I usually buy a month at a time), slap in my debit card, punch in the pin and be done
The fact of the matter is, there's usually way less waiting in line at the machine, and the actual buying itself takes less time. I've no problem telling thank you to the sale's lady, but in most situations using the machine is just more handy unless I happen to have some other business to take care of at the store at the same time.
The same is true for many, many services that used to be handled by clerks: I'll rather do my check-in at the airport or the harbor via a machine because it's easier and quicker, no need to go stand in line to buy concert tickets as I can buy them online and print them out or just have 'em read the QR-code from the phone screen, etc...
So unfortunately no, I cannot agree with this" you don't have to thank the machine" -BS. The machine gives me the exact same end result as I'd get from a person, except it usually does it faster. Unless the product/service I'm buying is so complicated that I need a guy there to help me figure out what I need to get, having a person there brings no additional benefit for me as a customer.