You assume that small issues are ever prioritized in the first place. My experience with large tech organizations is that their priories are driven by internal culture, not best practices, just like any other company.
Although I haven't worked at Twitter, if it is anything like the places I have worked at, the small issues get ignored because nobody makes their career on things that don't show up on investor / shareholder / upper management radars. If it can get papered over so it ends up being someone else's problem in the future, what actually gets worked on is flashier things like redesigning the timeline AGAIN so users spend more time on the website or (in the case that caused me to work for small startups again) spend three weeks deciding on a super trivial design decision with 12 stake holders.
Although I haven't worked at Twitter, if it is anything like the places I have worked at, the small issues get ignored because nobody makes their career on things that don't show up on investor / shareholder / upper management radars. If it can get papered over so it ends up being someone else's problem in the future, what actually gets worked on is flashier things like redesigning the timeline AGAIN so users spend more time on the website or (in the case that caused me to work for small startups again) spend three weeks deciding on a super trivial design decision with 12 stake holders.