Absolutely agree, but rather than temporally separating facts from critical thinking ("facts/knowledge are the beginning of learning") the two aspects (facts/knowledge and critical thinking) should be taught simultaneously--with the use of the critical thinking aspects to illustrate the "why" on the facts, AMD the facts to support the logic behind critical thinking as examples.
Roo_steer is right, most teachers just don't have the ability to teach critical thinking. This is what happens when teachers don't have practical experience, and are educated in education, by those educated only in education. Similar to how people without economic experience make glaring errors in explaining economics.
I believe the reason why teaching was better in the 50's/60's (the rapid rise in academic performance in the US) was the teachers HAD the practical experience...since there was high demand for teachers, and little schools that taught teaching, the teachers were pulled from actual practicing jobs (e.g. Engineers, etc) and thus had the actual experience to teach critical thinking (also, since most middle-age males in that era were military, they had brought with them the critical thinking/decision processes that are taught in the military). As the teaching demand continued, and those folks got older, schools began to respond by creating teaching degrees, and the practical part declined...teaching unions then gained power, AMD in order to secure it, created regulation that emphasized certification rather than experience as a qualifying metric, further skewing the capabilities of those "qualified to teach". While the ability to teach is a requirement to teach, it is secondary to the ability to educate, something we have forgotten--if the individual can "teach" but doesn't have the wisdom to transfer, the ability is useless in education. While most practicing professionals have the wisdom that could be communicated, few actually can teach, however what we forget is that people with no practical experience also cant truly educate, regardless of their ability to communicate.