@Hideout0 You are not wrong, but many people don't even think of purchasing travel insurance. You have no control over the volcano and neither does the guest. Same for all the hosts and guests in Texas and Florida. Imagine not only loosing income, but your property as well.
By using Airbnb's platform for your rental, you agreed to Airbnb's Terms of Service. Essentially it is the contract between you and Airbnb. Part of that contract reads as follows:
"9.5 In certain circumstances, Airbnb may decide, in its sole discretion, that it is necessary to cancel a confirmed booking and make appropriate refund and payout decisions. This may be for reasons set forth in Airbnb's Extenuating Circumstances Policy or (i) where Airbnb believes in good faith, while taking the legitimate interests of both parties into account, this is necessary to avoid significant harm to Airbnb, other Members, third parties or property, or (ii) for any of the reasons set out in these Terms."
If you were renting your space on your own, you would be the sole determinator of whether a guest would receive a refund or not and the guest could use travel insurance (if they purchased it) or sue you for reimbursement.
It is very unfortunate that there is a potentially active volcano in your area which causes the alert to go on for months creating loss of income.
I hope you and your family are safe!