"Screw tradition, if you're a fixture in the way of the leaders you shouldn't be racing." ??!!!
Where do you think tomorrow's leaders come from? They don't just show up and run up front from Day 1. Hendrick, Gibbs, Penske, Childress and Roush took years to get where they are today. Think they should have packed it in when they were getting lapped by Richard Petty and Jr. Johnson and the Wood Brothers? And it's not just drivers or teams - some sponsors get their feet wet via the smaller teams before making bigger commitments. If you get rid of backmarker teams you shrink the field by about half. Do you think fans will feel like they got their money's worth if there are only twenty cars? Even then there will still be slower cars... would you continue to pare down the fields, getting rid of “slow” cars, until there are only a few cars left? Competition for limited starting spots was supposed to keep the jamb cars off the track, but the economy has instead forced officials to cut back the number of spots (and they’re not even always filling that smaller number).
"Do you think that merging the truck and X series would be a good idea or would it just make a bigger mess of things?"
Bigger mess. The cars of the two series are too different so you'd either have to create a new compromise car or you'd have to force one group to get rid of their (now worthless) cars and build cars for the other series. Either way is a big expensive learning curve for a bunch of teams, and not all of them will do it. Even if you managed to merge them, the same cream will rise to the top so after the initial dust settles you'd end up with about the same number of fast and slow cars.
"it is a huge step from Super Late Models or ARCA to Sprint Cup. There is a good rational for a couple steps in between."
Yes there is. The problem is that the expense step has gotten too big, particularly today after three decades plus of sour economies. It's extremely difficult for a Regular Joe racer like Richard Childress to work his way up from local tracks to the Cup Series. (It wasn't easy for him, but it would be even harder for him today.) There are things NASCAR could do to squeeze some expense from the cars, but current management doesn’t understand racing so we get the demise we’ve all noticed. There will always be new faces coming in who are related to the old faces, and a few outsiders who have money, but fewer and fewer types like Alan Kulwicki. Which means there will still be a show, but maybe not with the “best of the best” as advertised.