IMO, domestic travel rarely if ever justifies the need to purchase insurance and really for foreign travel the biggest part is medical coverage.
Luggage is rarely lost, more often delayed, which most insurance has delays, and honestly even if it is delayed do you really want to go shopping on vacation for a few hour delay or would you rather just enjoy it and make sure you packed the necessities in your carry on (think medicine, contact solution, etc.)
Airline delays happen, but insurance doesn't offer much in the way of help, if you're cancelled the airline will rebook you. You might need to get a hotel for a night if you're in Disney, but it's manageable without insurance (and probably will cost less then insurance unless you return to onsite). Orlando isn't known for a lot of hurricane issues.
Again, bad weather rarely effects Disney outside an early closure/delayed opening. Even during the bad hurricanes in I think 2005, where they crossed over Orlando, Disney reopened after an early closure the next day with just minimal delays/closures to rides.
In the end, it's ultimately your choice, but in the grand scheme of things, the amount the insurance costs rarely justifies the risk. Remember insurance is meant to cover costs that would be a large loss, in most cases domestic insurance doesn't cover one as most costs are refundable, with minimal outlay to change/cancel fees (mostly applicable to air) and insurance only covers actual loss, if something is refundable or you are not charged, the insurance won't pay in addition.
