Ibanez RG7421 (Standard)
Ibanez MIJ RG420AH (Standard D)
Taylor 110e Acoustic (Standard E/Eb)
Peavey Raptor II (got for free from a budddy for covering his shift one night haha)
Aria 1970's era 12 String Acoustic (don't play, bridge is pulling up)
Now, my 7421 is the go-to guitar for me, and I keep it in Standard. The Taylor sits in the bag until I'm ready to jam on it, and the RG420AH sits on the stand as well. I love having the options of playing different guitars, but I could easily get away with having the 7 and the Taylor. I think once I've got my life in order I'll start saving for some really nice higher-end stuff, but until then I don't see the need to go apeshit on collecting anymore. I got to a point where I was more worried about getting nicks and dents in the guitars than I was about how they sounded, and that was when I knew it was much easier and cheaper to craft your tone with what you have than endlessly search for the coup de grace of guitars.
The other side of the debate is the idea of guitars as artwork. If I had the money, I would spend it on beautiful guitars that I could stare at for hours and not touch. Yeah, they probably play amazing and sound just as good, but, for me, a guitar is a piece of art. I've seen paintings and all kinds of "real art", but I would take a Mayones with a spalted maple top over any museum art any day of the week. I know many people feel the same, in that looking at a guitar is (sometimes) just as satisfying as sitting down and ripping on it.
In short, people have different needs for guitar. If you think you could be fine with just one guitar, then why not just have one sweet guitar that works for you? As cool as it is to say "Yeah, I've got about 15 guitars right now", its just as cool to say "I've got one badass guitar that does everything I need it to and more".