Ok, it sounds like you make an effort to glue on the end cover strips very well, that's good. The reason I dislike the glue on stuff is that if not buffed correctly, and it's catchy then it will come off eventually, and that'll look a lot worse than a metal screwed on strip.
So the glue on strip is more prone to failure in my view.. but perhaps I'm wrong, and if done correctly, will last for ever.
50 Euros per join is good... 200 per join would be too expensive, and would make the joining striips more attractive, especially to people paying 2,000 to 2,500 for everything. like the IKEA poster.
Yes, of course equipped professional tradesmen would prefer to do better work, but if the customer can't pay then doing it the cheaper way may be best. I think painters would often be painting colours that they themselves don't like... they just have to take it.
I don't follow the angle measuring technique. It would work in some situations butnot all... not for U Shaped worktops, where the ends of the U are trapped by full height cabinets. In that case some guesswork is required,.. and yes, an experienced person can do a lot by guessing, or by using his eyes.. but an upstand or tiles at the back will often cover up a non-perfect corner, so perfection is often not required... (hard to describe)
Yes, people who pay cheap get cheap work... that's obvious, and what the customer expected.