With retirement just a couple years away, I'm definitely thinking about retirement housing, and I agree with some of your points -- but not all of them:
1. The house is paid off and it would cost a lot to move.Yeah, I can see that if you bought your house years ago, buying something at today's prices might not make sense -- even without the costs associated with moving, which could include not only the actual moving but also new furniture, curtains, etc. to fit into your new place.
2. I could find a less expensive place, but not better climate (coastal SoCal).I suspect this has a lot to do with the fact that you're used to this climate. People in icy cold locations, for example, are just as sold on their locations.
3. I don't mind home maintenance and I have plenty of time to do it. I like having room for all my tools.Fair enough, but what if the day comes when you're not able to do these things? Paying for them in a smaller place would cost less.
6. I have the option to use the extra bedrooms for rental income if I choose to.Now I think that one's a rationalization. Even if you wanted to rent your extra bedrooms, this kind of "isn't done" any more, and I don't think it'd be all that easy to find a renter. However, if you ever need one of your children to move in with you, or if you ever need a paid caretaker to move in with you, you'd be set.
I won't downsize until I am physically or financially unable to maintain my places.
Might actually up-size and add a new barn.
What you might not have considered: If you wait until you CAN'T manage your current home, you may find yourself in a crisis and it may not be so easy to move.
For example, let's say you can no longer manage the stairs in your apartment. At that point you probably also can't manage all your packing and moving on your own, so you have to pay someone to do it for you. If you wait 'til you can't financially manage your current house, you may not be able to pay for the little things you ought to do to make it sellable (like repaint the bedroom and replace the nasty carpet in the living room).
You know how people buy a starter home, then trade up when they have kids, then trade down in retirement? We are just going to skip that middle part.
Yeah, we're doing just what you recommend against, but it has worked well for us. We first bought a small, affordable house ... but when we had kids, we needed more space AND we wanted to be in a different school district ... now what we want for retirement is essentially the same main rooms we had "back then", but we want larger closets, a nicer kitchen, and a bathroom that'll be good for aging-in-place.