I used to despise the GIMP because of its interface. All those clunky windows... Yes, I'm aware that there are forks which add MDI support, but meh, I want to use the official version..

Then I switched to a tiling window manager and now those horid multi-window layouts are... the greatest thing ever. To me, its as if they have a single window layout, but with a huge amount of flexibility in how I want the layout. Now I like the GIMP and its multi window system and dislike MDI/single layout programs :D

So.. an interface is the best thing ever to one person and it turns another person "blind".