It's absolutely unethical and they should be ashamed and held accountable. They have something like ~$250,000,000,000 in cash and they are just robbing their customers twice by denying the problem they created and not paying appropriate taxes in their countries either. They've optimized to be incredibly selfish.
The chassis are virtually the same, the new MBP is just a speed bump. They could design new keyboard to be backwards compatible with the old mounting points and connectors and simply replace old keyboards with the new ones. There is no new ground breaking features between old and new keyboards apart from that membrane. I think they just hope that after replacing old keyboard with the same ones will be enough to push those units trough warranty period and if keyboard fails after warranty then a lot of people will be pushed towards buying whole new unit. The second reason is that during the recall Apple is able to push out old stock of keyboards, if they would use new design keyboards the old stock would have to go to recycling witch is costly.
I don't think the worse typing experience (but better reliability) is one of the selling points for the new MBPs. I think 32GB of RAM (finally) on an MBP is.
Apple products are simply not designed to be serviceable. I have fond (ish) memories of Dell shipping me several $90 keyboard assemblies for my latitude, under warranty, when keys would start acting up; before requesting the third replacement, I noticed there was a bit of aluminum that just needed to get bent back to shape to fix the issues, and saved a bunch of hassle. But I'm not sure if anybody still makes laptops where they've used the space to made things modular enough for economical spare parts.
I think Thinkpads are still pretty good at this although even they started to fall behind. I remember the days when Apple was designing hardware in a way that was allowing easy access to internals for a pro user. All those handles, easy access doors and trays sliding out with the internals, good old days.
I had an early 2016 that had a keyboard replaced, then a complete replacement under warranty with a new 2017, and I'm sending it away for another keyboard replacement tomorrow. For a work machine, it's pretty ludicrous that I'll have been without my primary computer on 3 separate occasions within 18 months.
The woman in the apple store hinted that if I had to get it replaced more than once, they might just upgrade it to a new one like they did with my 2016 -> 2017.
Fixing a fatal design flaw shouldn't be a unique selling point for the newest models.
[1] https://www.theverge.com/2018/7/16/17577478/apple-replace-ma...