Hopefully not repeating what I've already said, but some of the "brand factor" is I think that Bose markets their products (particularly their headphones) as "audiophile quality." Problem for some is, to some consumers, their headphones deliver that. Sound appreciation is a subjective thing (imho). If that same consumer was offered a comparison between Triports and comparably priced, top-rated headphones, the consumer might realize, "Oh, I like these other ones better." Notice I said "like" not "these are better."
A smart marketing strategy of Bose is that their headphones (and other products) are positioned in listening stations at retailers where you CAN'T compare with other, comparably priced units. I haven't been inside a Best Buy in ages, but at Target, BJ's (warehouse club store), etc. you can "hear the difference" in the Triports ... but not really, everything else is in bubble packs. Comparably priced audiophile headphones aren't even on sale there.
I recently replaced my older Triports' (around ear) cushions with $17 replacements, and then offered the Triports to a coworker. I told him they weren't worth $135 new, and even at the $99 price point, there were comparable headphones that were highly regarded in sound quality. I asked him to Google a bit and tell me what he though was a fair price for headphones, extension cord, and bag. He offered me $40. So ... I think the Triport AEs are worth ... $50-60 new.
I have some new Triport IEMs that I got free from a credit card rewards program, and I like all the accessories (lanyard, shirt clip, case, 3 sizes of plugs; oops, NO extension cord). They sound fine, are comfortable (I wore tight ear plugs for many years in aviation, and have no need for them now). Of course, they were free, so its hard to be disappointed.
As far as speakers, the last time I did an in-store comparison with the same audio source, I compared their center channel (CS-1?) with others, and they sucked mightily. They didn't even sound as good as their low-end 201 bookshelf speakers. Rewind to 1992 or so when I compared 401 tower speakers with several other comparably priced high-end brands, and there was no comparison, the 401s sounded clearer, deeper, more alive than all others. They still serve me well. A few years later, Consumer Reports rated their 301s with the flatest response curve of any speakers they tested; I now have a pair of those for my rear surrounds. They've slipped in the ratings since, and I believe the newer 301s don't have as much sonic dispersion as the model from the late 90s.
I recently listened to their latest computer speakers (Companion 5, 3.1), and they sounded great. But for $399 they'd better sound good. The $250 Companion 3s, not so great, and you can get better sounding speakers for that price point. Again, I listened in a store where you couldn't listen to the competition (not sure there even were other $400 computer speakers for sale). I have
the original MediaMate computer speakers playing off an iPod (line level out) in my bedroom (that's my pic on Wikipedia), sound great. their current "computer speakers" (similar form factor, 2.0, angled wedge), Computer MusicMonitor, sell for $399, and having listened in a Bose store, I can assure you
those are NOT $399 speakers.
All this is to answer, what's so bad about Bose? It's not just that their products now are -- generally -- not as good as they say they are (but once were), but they are priced higher than comparable quality products, and positioned for sale in spaces where they can't be compared, so their marketing hype has greater influence. It doesn't mean all their products are trash -- some are good for their intended use -- but these may be the exception. Due to their retail contracts, buying them at the price point that is commensurate with their quality is, shall we say, problematic unless you get them used.