Haven't bought a Ubisoft game for a while. It's a shame they don't realize that some of their users may go to prison, or travel for long periods, or join their country's armed forces, or just fall on hard times.
Plenty of reasons why they wouldn't log in. At least with Steam (for now, and hopefully for the future) I won't lose my (non-Unisoft) games for not logging in. Hell, in the early days of Steam, I once didn't log in for four years. I was amazed that my account was still there when I did finally return.
I made my steam account when I brought the newly released half-life 2 then didn't log in again for over fifteen years, I had to find the original CD to get the product id but they let me back and I could play through half-life again - it's funny you don't really notice how good valve is as a company until you compare them to literally everyone else.