While an emulator's primary job is to emulate, there's usually a lot more that goes into a good emulator. For Dolphin, it may feel like a lot of work has gone toward luxury features and optimizations rather than improving accuracy and compatibility. For example, Ubershaders is a wonderful, game-changing feature, but it can't fix any bugs in emulation. With another of those huge features on the brink, it's important to highlight that no one has forgotten about Dolphin's weaknesses - it's just getting harder to fix them. Most of the games that no longer work in Dolphin either require better timings (which slow emulation and need to be hardware tested,) or rely on undocumented behaviors that have to be painstakingly sought out, rather than stumbled upon.
Case in point, fixing one of those cases could require weeks of devotion and every development tool in our arsenal just to locate the bug. With Red Steel, developers ended up having to reverse engineer why an engine bug affected Dolphin but not the Wii.