Why do golfers have 9 irons and 3 woods in their bags? To have more control on how the reach their goal, whether that means driving the ball with a 3 wood out 200 yards to the center of a dogleg to the right, as opposed to using the driver that would take them 250 yards into the rough. Or using the 9 iron to drop the ball 80 yards onto the green as opposed to using the 7 iron that would take them over the green into the sand trap.
I have collected trumpets to get me to reach the goal I have toward the gig or session I am hired to play. Through trumpet hangs and visiting my locally favorite music stores, I get to sample horns that when playing, places each one into the context as to whether that horn will help me optimize the quality of the type of performance to which I bring the instrument.
Let me explain: I have two flugelhorns. I use one for a back up (in case the other is in the shop which has happened on different occasions). I then choose the Getzen Eterna when playing outdoor venues and more contemporary (jazz rock) songs as it projects very well. I choose the Kanstul 1526 for venues that will be in small, intimate clubs with more rich ballads being used for the set list.
I have accumulated three lead horns, and must admit, two of which I rarely play out anymore. As I was unsure if my Harrelson would ever materialize, I first used the Super Recording and found it's brightness and ease of playing filled the role as a great lead horn. I then after several years of coxing with the price coming down each time, decided to adopt the Getzen Power bore, and that horn was not only efficient and bright, but also had laser crisp slotting and then became my lead horn of choice. Then my Harrelson came through and that horn is just the most amazing lead horn as it takes the qualities of the other two to another level... and it is nice eye candy.
My Martin Committee, that one I take from my bag to play with small ensembles.
My Olds Recordings, I use for classical work as they have a bold resonance that announces that a classical piece has arrived.
My Ambassador, I take with me when I travel on vacation as if it gets lost, or stolen from the room, it is easily replaced.
My Allora Pocket trumpet is another travel horn that goes with me on longer trips when I have to pack more cloths in the bags.
So that is how I rationalize my "Reasons to collect trumpets?"