I don't think it's a quest for any grail.
Some people like depth of experience. They want to take one aspect of their life and push it as hard as they can. You see that in musicians all the time. To be a great musician you pretty much have to find an instrument and obsess over it and it alone. That leads to musicians latching not just onto a type of instrument but onto a specific instrument, this guitar, this violin, is special because the musician has spent years of their life mastering it.
Others prefer bredth. They want to be able to know, from experience, about all the variations. They want revolvers, pistols, rifles, shotguns... bolt, break, semi-auto, pump, single action, double action, rimfire, centerfire, scoped, peep-sighted, partridge-sighted, diopter-sighted, laser-sighted, folding, telescoping, take-down, built-up, on and on. They aren't likely to master any of those to the level that the depth-focused individual will... but (switching back to music) they are a lot more likely to pick up an instrument they've never (or rarely) played and quickly learn enough to produce a tune. They can also tell you, from experience, the real world difference between Nikon and Leupold optics, between savage and mauser actions, etc.
The first group is really lucky in a lot of ways. They can buy one gun, or musical instrument, or whatever, and that'll keep them entertained for years... their whole life even. They get off cheap and they are often unbeatably good at what they do. How can the average multi-interest person compete with someone who spends all of their time and energy getting good at one thing? Think of bodybuilders, musicians, atheletes, competitive shooters, and so on spending 8+ hours a day training their one skill.
The second group... well, they'll either spend a lot of time scrounging, swapping, bargaining, and building all the variations they need to stay interested, or they'll spend a lot of money buying and figuring out storage for new variations their whole life. The only compensation is that they lead more complete lives in general...they are more rounded as people.
The only difference between the constant traders and the guys with dozens or hundreds of different guns is that the latter group can afford to tie up more resources in guns. Either they have more money/time or they have fewer other expenses.
