Lee, some of that depreciation is that you expect to do work on a traditional home. Yes, even to the point of ripping out and replacing walls.
I have some philosophical differences with the way the market 'works', and I see the 'common way of thinking' sold by the real estate agents and everybody else as the reason behind the housing market collapse.
So I'll list some points:
1. Houses do NOT actually 'appreciate' in value in most cases. What they actually do is depreciate slower than inflation.
2. Houses can maintain and increase their value through renovation and maintenance work. IE you put more resources into the home, it becomes worth more.
3. What generally appreciates is the land the house is on. But this is only true when the population is increasing, or an area is 'popular'. See Detroit for were the land can't even keep it's value.
4. You are generally far safer viewing your home as a capital investment for the most economical means of shelter of a given quality. IE 'it's cheaper than renting', than you are viewing it as part of your retirement 'nest egg' with the intent of moving to a cheaper place when you retire and the kids are out of the home.
Now, consider a mobile home.
1. Generally speaking, the owner doesn't own the land underneath the mobile home, so any appreciation the land doesn't help them.
2. Because it's viewed as a depreciating asset and is generally owned by poorer people, the maintenance doesn't get done.
3. Because they're generally purchased by poorer people, not only does the maintenance not get done, but it's built cheaper in the first place. Not necessarily true today - look up 'manufactured home' vs 'mobile home'.
4. The better constructed homes of today tend to retain mobility better - so moving one from a trailer park to a permanent spot that you actually own is more possible.
So yeah, trailer homes* can be a trap. But if you're aware of their quirks, they can be a worthy choice over a traditional home in certain circumstances.
That being said, you could and CAN purchase a mobile home that is as well or better constructed than your standard on-site built house today, but perception is a thing.
*I'm not sure of the terminology, but here's my take, and why I consider 'mobile home' something of a misnomer.
Mobile home: To me, these are the 'homes' that are actually built to be moved while occupied. Some have engine, driver's seats and all that, some are designed to be towed. They're built so you can put at least tens of thousands of miles on them. Due to this they're more limited in size, and appliances have to be special built to take the vibration and such. Cabinets will have locks or 'strong' magnets to keep them from flying open while being moved. They'll have a septic tank and water supply 'built in'.
Trailer home: A step closer in construction to a normal home, they'll actually have drywall, more normal appliances, and are designed to be hooked up to a water and septic system on a continuous basis. Generally not worth the effort to move once they've been in place for a few years, though the better constructed modern ones may be. Moving is much more of a pain, because while they've been left on the 'trailer', the trailer itself was probably cheap, the tires and maybe even the axles need to be replaced, the utility lines removed and secured, everything inside secured or removed, etc... Can also be a 'double wide' in that you match 2 trailer sized segments together. Otherwise they tend to be rather small for a modern family.
Manufactured home: Yet another step up in quality, these homes can count as the same as a on-site built home, and are often actually built 'tougher'. These ones are taken OFF their trailer at the install site, and placed on a permanent foundation. Moving one after the fact would only be a shade easier than moving a traditional house(which can be done). They often have basements, garages are built along one side, etc...