As a training provider we are of course biased, but i am also a tiler of over 20 years, and as others have said many times `you cannot teach experience` but what can be done is you can be taught from experience, thus saving a lot of wasted time, pretty much most time served fixers will condemn short courses, this is for a number of reasons, firstly they spent years learning their trade, and cannot accept learning in a short period could suffice, another is most do not know what is being taught, and this varies dramatically, most have seen so called Tilers who have finished courses with no idea! that will very much depends on who and what they are being taught, for example you can be taught to set out your tiles on paper or any 1 wall, but this does not teach you setting out, you will need to be taught to set out many types of ROOMS with problems, different size tiles etc.
But some people can definitely do 3-4 weeks good training and then work as a domestic tiler on standard work with no problems and too a very good standard!
Anyway i am happy to answer any questions or concerns.