i dont think the tech cert (i presume thats what you mean when you say C&G) course is rubbish. in fact id say its very good, however its reputation is rubbish which makes it of low value.
let me explain, the old apprenticeships they had craft certs and advanced craft certs, the tech certs are very similar they teach the underpinning knowledge. apprentices did 1 day a week in college (not collage) and 4 days with an employer. The mix of underpinning knowledge and skills and workplace experience meant after 4 years you had some good overall awareness and skills of the trade.
Now centres run the courses for full time students, ie not in the trade. This is due to large demand, students want these courses. They then complete the course, have in most cases no experience of working on site and therefore cannot yet put the skills/underpinning knowledge into practice. They then call the qualification rubbish!!!
You will see threads on here from people really pushing to do these courses and then complain afterwards that they are no good, remember college course is 1/5th of the training, the other 4/5ths coming from site, if you bi-pass 4/5ths of any training what would you expect?
If you or others choose this route fine, but realise what it is and where your skills will be after the course only.
In an attempt to plug the gap we have the nvq to prove experience, hence the tech cert is not recognised as you may not have relevant site skills. Both are C&G, the NVQ being the industry standard