There's too much misguided hate about Roman. He may be trigger happy, but from his side of story, he doesn't just expects trophies, he wants the team to play in very specific style. This is core element in his longterm bussiness plan for Chelsea. Even Roman can't keep throwing 200milion at the club every year, and the only way to challenge marketing power MU or Real have, is to play attacking, dominating football. That's the reason for this obsession with Guardiola, he's one of the very few active managers who have accomplished such style at the top level.
A lot of managers promised that, signed the contract , but then attempted to do their own thing. And when it comes to RDM, well he's a nice bloke, but team didn't have any style at all, cant have longterm success in todays football when fielding 4 people who don't contribute to defense.