Investigating options to redo the flooring in some of the house, I
came across what seem to be traditional style tongue and groove
floorboards - but made of spruce which I believe is a rather soft wood
for a flooring application.

See http://www.wickes.co.uk/invt/124419

Now on the package for these boards it specifically says not to use
this as a finished floor surface, but more for replacing existing
floorboards.

My question is - is there not a reasonable way to finish this sort of
wood so that it could be used as the finished flooring? It could
certainly look very nice and I don't mind trading effort to save some
money if that's what it would take. But is this a false economy
somehow?

Any ideas if this is a realistic prospect?

Thanks,
David