Airbnb didn't invent the vacation rental. People have rented their place to vacationers since forever. There were and are multiple companies and websites that did that long before Airbnb existed.

Airbnb just made it easier and thus more popular to rent your home or room to travellers.

Airbnb didn't innovate anything in the space as far as I am aware of, except for a great user experience.

The only people to blame in regards to vacation rentals raising housing prices are the governments that set and enforce the rules. As long as regulating authorities allow private residences to be occupied by renters on a short term basis, then investors are going to buy property and rent it that way.

Airbnb's intended usage from the beginning was to rent out the unused value of your home. Which would actually lower housing prices since it allows you to use the housing more efficiently. But now bigger players are buying property for the sole purpose of short term rentals which decreases housing supply.