I do not consider scales to be evil or out of place. They are simply part of the low impact repetition toolbox that can give a student patterns for recall in many different contexts. They are an essential part of holistic development in my world. I use them for teaching just about every technical discipline that a trumpeter must develop: time, transposition, intonation, articulation, range. Naturally they are not the "only" things taught. We had a discussion about proportions during practice/ lessons at TrumpetMaster. I remember agreeing with several about approximately 1/3rd body use, 1/3rd technical studies and 1/3rd tunes/repertoire. We discussed the issues surrounding a "too rigid" structure and having the student in clear focus. During periods of high dedication, we the teachers can raise the bar at many levels - if we have a method to even define the bar..
My personal view is that we must feed our internal reward system. Measurable success changes the way that our central nervous system processes stimuli. Mosche Feldenkrais and several Yogis deal with this at an even higher level.
Proper use of scales makes the Haydn, Hummel, Neruda, Tartini, Verdi Requiem, Tschaikowsky 5 certainly "easier".