Well, I was pondering this myself recently while sitting on an artificial concrete boulder at the new Cuningar Loop bouldering park in Glasgow. Does it really matter that a boulder is made of concrete, surrounded by plantation and skirted with kind gravel traps rather than tree roots and spikey boulders? Isn't the 'real' thing so much better: the isolated erratic bloc deposited by geology's long-term aesthetic artwork? Well, yes, that's entirely up to you, but sometimes the artificial saves the day ... I was scuppered by Glasgow's cross-town traffic and turned back to my local artifice that is Cuningar to climb the blue circuit I had imagined as something akin to the real Fonatainbleau. With the wind shivering through the tree canopy and the sun catching the light-coloured moulding of the concrete, I was almost in the real thing. That was good enough for me - Plato can cast all the artifical puppet-shadows he wants, I'll accept the story it tells!
If you want to sample the bouldering park, here's an access topo for a representative 'blue' circuit of 22 problems between Font 3 and 5+. Dropbox PDF topo >>>
Or visit the Boulder Scotland companion website >>>