I think Lenovo still makes quality products, I'm currently using their x220 (with Mint). I suppose it's possible that their newer models are worse, but I'll give them the benefit of the doubt. The x1 carbon looks like a cool machine to play with.
I wouldn't bet on Dell, and HP ever getting back to their glory days, but I wouldn't count out Lenovo, Samsung, Google, and Asus (Asus zenbook prime, looks amazing).
This is my take: if it works for you, and you like it, then go for it. Some people, like you, obviously like ThinkPads, some people like Dells. We're all different and we have different tastes. We should respect that.
My issue with the article is how the author prepositions the argument for her computer with "Apple didn't fix my laptop to my liking, so I got a Dell and now freedom!" The difference in freedom between Apple and Dell is nil, and I'm arguing that the difference between OS X and Ubuntu is worse because at least OS X doesn't ship off your desktop search results to third parties or show you ads in the results.
I wouldn't bet on Dell, and HP ever getting back to their glory days, but I wouldn't count out Lenovo, Samsung, Google, and Asus (Asus zenbook prime, looks amazing).