I preferred the L-form plug you're describing, but that's not my main issue.
I used an MagSafe 1 L-form one for a couple of years as well, and now the MagSafe 2 T-form one.
With the MagSafe 2 the cable sheath started to become kind of porous and would fray after a year at the connector, which I had to fix (used some excess sugru my sister had lying around). This worked, but made the connector end a little heavier meaning even more chance it will slip if the laptop is moved ever so slightly.
Another half year later or so the cable showed the same symptoms in the middle of it, where now a large area of the cable sheath would become rigid, porous and would eventually rip open. That part of the cable was usually in the air, did not touch anything and of course was not in front of a heat source or anything like that. Imagine my confusion. I patched it up again with some electric tape.
I never had these problems with the MagSafe 1 cable. When I googled a bit, this seems to be a common issue for Apple cables, and a lot, lot, lot more common for the MagSafe 2 (anecdotally from what I saw in the google results)[1]. That and a lot of people would have the entire cable fray and stop working (usually at the power block end), at which point you'd either have to open up the thing and solder it together or more likely buy a replacement for 80 bucks, but that didn't happen to me (yet) thankfully.
I've used a lot of laptops, and while the magnetic connector is certainly an improvement (so of course, Apple replaced it with USB-C), I never had a cable slowly shed the cable sheath before. That's what I meant by bad design.
As far as I can tell, things didn't improve. Instead Apple decided to not even ship a cord with new models, so you either have to buy one yourself (another 20 bucks) or plug the power block directly into the wall socket. I'm cynic enough by now to believe they didn't stop shipping one because they are cheap, but to make the packaging box "thinner".
[1] e.g. https://news.ycombinator.com/item?id=13307130