Bruce Prichard told listeners on his 'Something To Wrestle With' podcast that Bam Bam Bigelow and Matt Bourne, who was the original Doink The Clown, didn't see eye-to-eye behind the scenes.
According to Prichard, Bam Bam particularly disliked working with Bourne. They were programmed together in late-1993, and were supposed to have an extended feud that'd peak at WrestleMania X. That happened, but it wasn't Bourne under the greasepaint.
It was Bammer's real-life pal Ray Apollo.
Bourne left the WWF in late-'93 for personal reasons and trouble with various addictions. Swooping in, Bigelow suggested to company officials that Apollo was a much better worker anyway and would make more of the Doink gimmick than Matt ever could long-term.
That...didn't happen. Doink's babyface run opposite Bam Bam was a disaster, and Apollo blatantly didn't have the same maniacal appeal as Bourne. He was functional at best in-ring, and fans weren't fooled by the anonymous switch.
Bourne went on to claim in several shoot interviews that Bigelow was responsible for his departure from the WWF. They just didn't get along, and neither really enjoyed working with the other from day one.