No, it isn't. My home insurance covers me abroad. If i pay my ticket with Visa cc theres also an insurance with them. As if thats not enough, i also have the Kasikorn insurance, an option attached to my bank account/atm at Kasikorn.
At least once every trip I've used my home insurance , and they guarantee to cover the bill right away upon request from the hospital or clinic.
Triple insured, so no need to buy an extra.