I've used a T400 as my kitchen laptop for years, and recently put Win10 on it. I put my SSD in it, back with Win8. The laptop still works great, and it's my main PowerShell workstation - it's where I wrote my Arkdata player tracker static site. (Yes, I wrote it while standing in my kitchen.)
The market is the same, really. What you're seeing is the end of Moore's law, with 10 year old laptops still being effective compute devices. This wasn't true in 2005 - that 1995 laptop was painfully old.
When I said the market has regressed, I wasn't referring to the slowing advances in CPU performance, etc. Normally, such a slowdown would enable manufacturers to focus on creating better cases, improve peripherals, etc. Instead, the obsession with thinness and design fads has led to worse usability, much worse keyboards, fewer ports, etc., and maintainability is virtually gone as a concept.
Obviously, this is largely a matter of preference and I understand that many users care more about thin shiny things than robust cases or high feedback keyboards. That's fine. The issue is that the market segment that the classic Thinkpads used to fill is completely gone now and those users, however few, are stranded.
The market for laptops and computing devices has traversed us like an ocean wave. Where we were once among the bleeding edge for such devices, our obsessions - with connections, with customizability, with function over form - have left us among the long tail of compute users.
The market is the same, really. What you're seeing is the end of Moore's law, with 10 year old laptops still being effective compute devices. This wasn't true in 2005 - that 1995 laptop was painfully old.