Everything is important in the audio chain; it is true that the speakers are the last element in the chain (plus the room) and they can have a profound effect on good/not so good/terrible results for audio playback but consider those systems you've heard with otherwise good speakers pushed by bad or at least not ideal component choices including amp and pre-amp, digital front-end, cabling, power, etc....and the whole adds up to less than the sum of its parts so to speak. Conversely, remembering several systems with older or less expensive speakers backed by extremely intelligent choices of amp, front-end, cabling, power, etc...exuding much more performance out of a speaker than its price point would indicate and you see the other side of the coin.
There are also many examples at shows, etc...of so-called 'high-end systems' and speakers that simply don't sound good at all...
This 'religious debate' has no winner IMHO and often tons of personal agendas stacked upon it.....the entire system is important, the sound we are looking for, how we build it, how we choose compoents, synergy of each with the other, including speakers and room AND the musical material and quality thereof that we play...it all factors in.
My 2cents....