I agree with you there. Beats by Dre is a an extremely cheap product with someone's name on it. It is still possible to get good earbuds/phones but you will have to pay for them. I think the burn-in thing came from several different places. For instance, back in 2003 when you wanted to stand up a new server it had to undergo a burn-in period. the server was hooked up, and a special program was run. The job of that program was to put the server through it's paces. It was designed to keep it at full utilization for as long as you wanted. We usually kept is going for about 24 hours. If something was going to fail on the server, it was going to happen at that time. Not at some random time which usually ends up being when it costs the company the most in lost revenue and down time. Actually, I just goggled the term "burn-in" to see if what other uses existed for the term. Wikipedia lists my above description as the definition. So I feel kinda proud of that... Oh, and it has a little blurb about burning in earbuds at the bottom but who cares about that....
I remember burning in servers. I've burned in drives before. It was a 24 hour process designed to find the flaws before you put the device in service. Did you ever run across anyone who thought the server "ran better" after burn-in? I dunno. The whole thing is weird.
In the early days of hard drives, I worked for Seagate. Part of my job then was involved in the burn-in process. In those days, we'd make the drives seek continuously for 48 hours, and a few percent would always fail and be scrapped. We improved on the process though, and I developed the code we ran on the drives themselves during burn-in. We converted it from a simple pass/fail burn-in, to a flaw-mapping / media characterisation phase - so that, for the drives that survived burn-in, we would have a wealth of info stored on the drive itself. This allowed tuning of the read-back parameters later, which saved the company a shit-ton of later testing and flaw-mapping. The genius part was that all this manufacturing phase needed was a power supply for those units. Saved millions in test equipment costs.