I agree. Learn the process inside and out first with the kits. You'll know you're ready to make the jump to you're own recipes, when you see a kit and think to yourself, "I'd like this kit better if it had more of this and less of that in it."
However, there is something to be said about making "SMaSH" beers. These aren't kits. They are a single malt and a single hop. SMaSH = Single Malt and Single Hop. You'll learn the flavors of the base malts and the flavors of the different hops this way. This is an uncomplicate way to get into recipe design, while still keeping it simple.
You can even make a SMaSH to some styles. Such as Pilsner (all kinds), Vienna Lager, Saison, Munich Dunkel, Wild Ales, IPAs and even Barleywines. That last sentence was quoted from Brad Smiths blog here on BeerSmith forums on SMaSH brewing.
Once you understand the way the different base malts and hops taste and work in a simple recipe, you can then build from there by adding different specialty malts or adding two or more hop types for bittering, flavor and aroma.
If I were to start over, I would have started out kit brewing to learn the process and then went to SMaSH brewing next. I've made two SMaSH beers so far and they were as good or better tasting than just about anything else I've made.
I'm going back to basics soon and will be doing a series of SMaSH brews this spring and summer to increase my knowledge of flavors. I'm starting with one base malt (NW Pale) by Great Western Malting and I'm going to do some single hop experiments. If I can get enough fermentors freed up, I'll mash a 22 gallon batch and then boil four 5.5 gallon batches, each with a different hop variety.
So, you have options. No matter what direction you take, I'm sure you'll enjoy it and you will have great beers to enjoy and share with your friends and family.
Good luck and keep us in the loop on how your proceed and on your progress.