i do it because my strategies are so switched over to non spike climbs, and then to exercise those skills more too (especially at first on ez ones when trying to get hang of it at every easier oppurtunity).
Now, blocking out, or climbing steep, clean verticals on removals, more apt to use'em. But in fairly well scaffolded removals; or wearing them all morning because i need them once or twice, i make do without. If one section of a tree is coming out, and i can isolate it to spike only and it is steep or blocking out wood of it self with no were else to stand i wear em. Sometimes even on removals, i might climb up, then get them off as dead weight.
It is just what i've gotten used to and exercise to increase skill in.