People learn in different ways. It’s probably a mixture of habit and personality. My experience shows that I simply feel more comfortable starting to learn in a particular way (globally). At a later stage, I become more flexible, but it’s still my preference.
There is the global type, where people prefer the ambiguity of seeing the language as a whole. They start deducing what is going on through exposure and some hints here and there which helps them to broaden that holistic picture of the language. LingQ, Assimil and immersion works best here.
Next is the detail orientated. They like to see the nuts and bolts early on. These people prefer to start with reference grammars, teach yourself books, etc, building a scaffold upon which the experience of the language itself can be rested on.
Lastly are those who prefer to do. They love to do drills, exercises, etc. For this are things like FSI courses.
I’ve tried to start learning languages with a non-global approach and I really just can’t do it. Especially the drilling method falls drastically short for me and people who prefer it baffle me. I need to start with Assimil, Linguaphone, shadowing, immersion, etc. When I don’t have one of those available to me, I’ll take the dialogues from courses like TY, Colloquial and such to make a PDF out of them, then listen and read while looking up vocabulary. In that way, I’m fitting them into my preference. Later on, however, I can use the detail orientated approach to refine my knowledge. This is when I read/write out grammar, tables, etc, to see what I’ve missed. However, I never am able to do drills and exercises.
Mikebond, I get bored with the TY too! Unless I’ve done input with the dialogues, then go back to quickly learn the grammar (no exercises). I also agree that Assimil is cheap. It’s very cheap for the great quality and its ability to hold my interest so well.
So, all in all, I think that textbooks are very useful, you’ve just got to know how YOU can make the best of them. Trying to fit yourself into a learning style which isn’t for you, is a big cause of language learning failures, in my opinion.
P.S. Steve, I know you don’t believe that learning styles exist, but you do show all the hallmarks of a global learner who just happens to be opinionated. Said by a fellow opinionated human being. 