With money and space not an issue? What a wonderful contemplation! In that case I'd figure having only two guitars the person just hadn't met enough of them yet to fall in love with more, which I s'pose could be for many reasons, like busy with banjo or fiddle, or job or family.

Still, with no limit on money and space, only two from among six strings or twelve, blues drivers, fingerpickin' beauties, flatpick heaven...not to mention favourite tunings and the special feel and sound of each one...? [sigh] Sure, you can get by with one or two once you decide how to balance 6 and 12 strings vs nice one and day-tripper, dreadnought and (whatcha call the really buxom ones?) and so on.

But with money and space not an issue, that leaves time as the limiting factor, otherwise why just one or two? Okay, when it(they) is(are) your only true guitar-love(s), then it makes perfect sense to me.