Syd Barrett was not kicked out.
The first few albums by Yes didn’t sell very well, and they were on the verge of getting dumped by Atlantic Records. After original guitarist Peter Banks was replaced by Steve Howe, they found the stardom that had eluded them.
Peter Gabriel left Genesis before they enjoyed any real COMMERCIAL success. Plus he wasn’t fired, he kinda just…left.
Probably the poster boy for “Crap what did I do to my career?” although he did eventually enjoy some commercial success solo.
Dave Evans was the original singer for AC/DC and was booted before they hit it big.
He wasn’t really kicked out, he just kind of faded away with Gilmour covering for him at first for about a year. Also they already had a few successful singles and were successfully touring while Sydwas still writing.* See Emily Play* peaked at #6.
Actually, in baseball terms, this was a move that benefitted BOTH sides. When Gabriel was with Genesis in the Seventies, they were a prog-rock band that played long organ-heavy songs about the Meaning of Life. Now, I loved that stuff, but by the late Seventies, prog-rock was moribund. Gabriel got out and changed his sound entirely. When he left, Phil Collins became the band’s leader, and they adopted a much more pop-oriented sound. That’s why Genesis GAINED popularity and increased their record sales even as ELP, Yes and other prog-rock bands were collapsing.
Meanwhile, Gabriel sold more records than he ever had with Genesis.
So, neither side has any reason for regret.
You can’t be serious.
I guess his $70 million fortune will have to ease his pain.
John Curulewski was the original lead guitarist of Styx, and the band had some success in the Chicago area in the early Seventies while he was a member (I think he played lead guitar on “Lady,” their breakout hit). But they didn’t become big national stars until Tommy Shaw replaced him.
“Crazy Ray” Tabano, a childhood friend of Steven Tyler, was the original guitarist of Aerosmith. He left the band in the early Seventies, before they became stars.
By all accounts, he quit by mutual decision. Creative differences were part of it, but the main reason was because he was a Type 1 diabetic who did well as long as he wasn’t touring and engaging in the erratic lifestyle that went along with it. This was not revealed until after his death in 2008, from complications of that disease. 
REO Speedwagon had a couple of personnel changes early on as well.
Not exactly the OP, but Chevy Chase played drums in a college band called The Leather Canary with college buddies Walter Becker and Donald Fagen, who went on to form Steely Dan.
Interesting, I saw them around '89/'90 so I must have seen them without Grohl. They were only known locally at the time, and I thought they were terrible and I left after 3 songs. They definitely sharpened their chops when Dave joined.
My contribution:
The Beastie Boys originally had drummer Kate Schellenbach (later of the awesome Luscious Jackson). I don’t know if it was a “boot”, since they all remained chummy afterward.
And if the money wasn’t enough, there was also the sex with Rosanna Arquette.
I know Heart changed a lot before the Wilson sisters joined up - the band had existed for 10 years prior - but I can’t recall if anyone got kicked out.
Someone kicking themselves might be Gwen Stefani’s brother, who brought her into his band then quit before her songs made them a success.
Robert Fleischman was booted out of Journey and replaced by Steve Perry.
The original Journey was a VERY different band from what it became. Their original lead singer was Greg Rolie, who had been the organist and vocalist of Santana (that’s him singing songs like “Evil Ways” and “Black Magic Woman”). Their original drummer was Prairie Prince, who was replaced by Frank Zappa’s old mate Aynsley Dunbar just before they made their first album. Original guitarist Neal Schon (also from Santana) and bassist Ross Valory (of the Steve Miller Band) are still in Journey today, but Rolie and Dunbar left before they became hugely popular.
That original Journey was dedicated to long, extensive jamming and prog-rock/jazzy instrumentals.Their records didn’t sell well, so the record label told them to add a new singer and to start writing more pop-oriented songs. Robert Fleischman was the first new singer they added, but he didn’t stay long. They finally became huge stars with Steve Perry as lead singer and new keyboard man Jonathan Cain as primary composer.
I also remember reading somewhere (I don’t have a cite offhand but might be able track one down if pressed) that Geddy and Alex wanted to move beyond being a simple three-chord bar band, and Rutsey either didn’t have the chops or simply didn’t want to be bothered to play more complicated rhythms, so they parted company partially for that reason.
Does it count if the former member’s work was still part of the band’s success? The Gin Blossoms booted Doug Hopkins because of addiction and psychological problems, but New Miserable Experience was almost finished by that point, and the hit singles from the album were the ones Hopkins wrote (“Hey Jealousy” and “Found Out About You”).
The poor guy committed suicide when the band really took off.
Back when they were popular, I remember seeing a feature somewhere showing various previous iterations of the Bay City Rollers, who had apparently existed in some form for quite some time before they hit it big. They had been through many line-up changes, with nearly every original member replaced at some stage (and, I think, several of the replacements replaced in their turn), but a constant through most of their history was a guy called Nobby on lead vocals. Eventually, however, Nobby too was replaced, and they soon became stars.
Of course, as anyone who remembers that era will tell you, they were still total crap, perhaps one of the worst bands ever to actually have a sustained string of hits. One hates to think how bad they must have been when Nobby was still a member. :eek: