I'm not sure that's true though? They did quite alright over the next ~5 years or so and the way how Jobs handled the Lisa or even the Mac was far from ideal. The late 90s Jobs was a very different person from the mid-early 80s one.
IMHO removing Jobs was probably one of the best thing that happened to Apple (from a long-term perspective). Mainly because when he came back he was a much more experienced capable person and he would've probably achieved way less had he stayed at Apple after 1985.