Sorry... you said 'three campaigns in a row', which I thought meant you had three straight campaigns with 4 out of 5 members being full casters. That's what I meant by "every group", thinking you had three groups for three campaigns. If you actually meant one group but you went through 3 different campaigns with them, then I misunderstood.Sorry, where did I say "every group"? I said the last group I had. My current group doesn't. But, thanks for the assumption that it was my own incompetence that was the issue. Of course it could never possibly be that 5e has made casters so much better than non-casters and, frankly, made virtually every class a caster. 5 full caster classes, 3 half caster classes and 2 non-caster classes, both of which get caster options as sub-classes. Gee, I wonder why groups would be caster heavy?
And I made no reference to your competence as a DM. I said that your style perhaps encouraged them to play nothing but casters, and if you didn't like that happening anymore then you would be within your rights to start fighting fire with fire. I don't know if you already have or not previously as you didn't say... but you said you were annoyed by what was happening so I commented saying you should feel free to deal with it in whatever best way you could. If you took that as me calling you incompetent... my apologies. Didn't say it, didn't mean it.