Everything is task specific.

My car is a family car. Does that mean I wouldn't like a sports car or a 4wheeldrive?

Some of my knives are gentleman's knives, some are outdoor knives, some are kitchen knives. This Rockstead is a tactical knife. I happen to not have many of those (only one really) and I'd have no problem trading my current one in for one of those.

Likewise, some of my knives have a personal sentiment attatched to them because I consider the maker a friend or some such. There's plenty of reasons. Let's not pretend that we in this society only buy what we need as opposed to what we want.

The best reason when it comes down to it is:

I want it, therefore I want it.