fz04, you have a total misunderstanding of practical / theory / learning...
chicken and egg - you are claiming that the practical can only come after the theory... nonsense

where do you think that the theory comes from?
if practical always came only from the theory, then Google would (with all their PhD bods) have developed the perfect theory and then implemented it. The fact that they keep tweaking it / developing it clearly shows that this is not the case.
The simple reality is that theory comes from practical as much as practical comes from theory - if you are familiar with rapid development models then you will understand the approach (v. the waterfall methodology).
And that is how SEO works in real life - those experienced practitioners on here and else-where will have theoretical knowledge, but it is continually refined by testing / implementing / observing / analysing - adapting the theory, back to testing / etc. - i.e. in and out of practical and theory...
anyone who goes into the SEO industry on a theoretical basis will be useless until they have actually done some SEO and seen the results and then re-learned their theory
and just to qualify - I am a qualified teacher and do a lot of teaching in a number of fields - what I have posted above is known and accepted across education / research / training / etc. no-one would train as a teacher and know the theory and go straight into their first job without any practical experience... however people do go and get hands on learning - classroom based, augmented with theory, but strongly locked into practical experience and this is how teacher training is developing - practice is considered far more important than theory.
my experience in the IT industry (which is considerable) also demonstrates very clearly that the most competent designers / coders / project managers / SEO bods / etc. are those who learn by doing it (yes, they will read and absorb theory as well), and continue to do so through their careers... those with theoretical knowledge only soon get it knocked out of them by the reality of business
nonsense

the reason I use my accountant is that he puts more time into keeping up to date with the law (I don't have the time), and he has more experience of business accountancy than I do, by acting across a range of businesses - which brings a breadth of experience into my business...
I have no accountancy training, but am quite capable of running the book-keeping / doing a VAT return / end of year company accounts / P&L / etc. etc.
Similarly I have no legal training but did my own legals for a business I ran with major VC investment into it - and ran rings around their lawyers including finding some major legal flaws in their work...
I would suggest that perhaps you need some experience before you start telling everyone else how it is done!
There are undoubtedly cowboys on this forum as elsewhere - but I would be very cautious about making comments like this - you have no idea of the relationships / work done by those companies or the results gained for their clients...
Once again you are making theoretical assumptions without basing them into the practical reality of life.
Please do not confuse theoretical learning and practical ability - sorry, you are totally wrong - in fact your theory is clearly itself not based in the practicality of real life - once you understand that then it will make sense!
You need to pull yourself out of the belief that theory is all and go and get some practice - then you will have a far more balanced and realistic view on life!
Alasdair