Well, you did do a wee bit more than comment on the brand, to be fair! You said it gave off geography teacher vibes & was overly marketed wank that made women in their 50s look like they were in their 70s ...
There are lots of women in their 50s, 60s & 70s on this thread!! So I think people who wear a little or a lot of the brand will have been offended by that? Especially as your dislike of it seems to be a blanket one, where absolutely everything they do is frumpy & ageing. I don't agree that all of it is, though some is dated by current fashion standards, yes.
I actually don't own any Seasalt myself - but I wouldn't necessarily rule it out. Tbh there aren't that many brands that I would rule out entirely if I was challenged to put an outfit together from their range. I can think of a few that I'd probably find very difficult (Coast??), but I think I could probably find something that I could style & make my own from brands that I generally don't much like the look of, & don't buy from - eg Lucy & Yak, Hobbs, Phase 8, Karen Millen ...?
I am (probably overly) outspoken & honest in person - & I swear rather a lot too (Irish - on bad days, fuck is punctuation ...!!). I have a feeling you may be similar ...!! I have reined in my blunter comments since I came on MN though, as I realise it can be easy to interpret things as rude, hurtful etc when you're reading a stranger's words online with no context, facial expression or laughter etc. I did once really offend someone who'd posted a picture of (what I thought was) a really badly cut dress as a suggestion - I said that it looked cheap & nasty, & she came back to say that she already owned one & loved wearing it ... & I felt quite shit about myself because of that 😐
So now my innermost thoughts remain (mostly!) inner ... 😁!!!
(Feel free to tell me I've been a patronising, sanctimonious twat - as I probably have! It's ok, I can take it ...)