I think the statements by RockV and Ojgalli are somewhat reconcilable (and perhaps mostly reconcilable) if we accept that at least some of the sonic differences between different high quality upstream components are audible through low quality speakers.
And I think that is probably true. Obviously speakers and their interaction with the room are typically much bigger determinants of overall sound quality than electronics. But given the many factors and complexities that are involved in accurate music reproduction (a frequency spectrum that is many octaves wide; dynamic range that is orders of magnitude wide; transient response and recovery; imaging, etc., etc.), it stands to reason that if the low quality speakers get just a little bit of this complexity right, equipment-dependent differences in what is being fed into them will be perceivable.
Regards,
-- Al