Sorry, you're just wrong. What you're actually describing is that the introduction of the ATB system necessitated a shifting in skillsets so that the skills you acquired in the first three FFs (including mad grinding and casual exploitation of elemental weaknesses) were no longer as useful. That doesn't make the earlier games more strategic, it just makes them different.
The series as a trend has gotten more strategic over time, not less, because the options presented within each character class have expanded to include those which were originally encompassed by earlier classes.
FFIV is much more "skill-intensive" than FFI. The fact that you can't figure out how to approach many fights, and therefore have to grind where I don't, stands as testament to this.
We're running around in circles, but I think the point has been proven ehre: your dissatisfaction with the newer FFs doesn't come from a lack of strategy or skill in the games themselves, but simply the fact that you're not able to utilize the strategic skillset that is provided to you by the games.
The kind of tedium to which you subscribe, the simplicity and one-dimensionality that describes the gameplay of the older Final Fantasies, is not a bad thing. But it is not preferable to the richer and more detailed combat approaches needed in every Final Fantasy from IV to XII. Increase of options for every character has allowed for designs which make battles much moe involved and interesting. If you can't adjust to that, I apologize, but I'm also very, very, very glad that S-E doesn't cater to you.