because they don't actually have that money in their bank/savings yet. if they decided to pull everything together to get cash right now, I'm not sure they'll have over $1M.
they are not fully retired. he retired at 58 (the plant he worked at does some kind of point system age + years of service) and was just drawing from pension or what ever until he reach 65. they both saved well outside of retirement. she got forced retired and they gave her 3 years salary to walk away from her job (not lump sum, drawing normal monthly salary). now when they fully retire they may be millionaires.. but they will have another (hopefully) 20+ years to live off of that.