I understand what's being said with junction boxes where you can't see them, crimping being preferable, but -
1. How often do correctly fitted junction boxes come loose? I was at my old house almost 30 years and remember plenty of junction boxes in the loft for the upstairs lights. Not once did they come loose or cause an issue. There are plenty in my house now, still never had an issue.
2. On the assumption that they come loose on their own, surely the same must be true of everything as regards to terminal screws. Standard plugs for example. I can't remember one instance where I've had to undo a plug because it's come loose on it's own. I've got appliances a zillion years old, we all have.
3. Same point above for ceiling/wall lights, plug sockets, FCU's,etc. Never found myself having to go round tightening them all up.
3. Doesn't every house everywhere have junction boxes scattered around. I've just had an extension, junction boxes were used for the lights. And for the smoke alarms.
4. How many times have you guys got called out to a problem and it's been down to a junction box? Just wondering. And how many of those times has it been because they haven't been fitted properly.
Can't help thinking that this problem is minimal and that DIYer's are far better off using junction boxes as both DIYer's and electricians have been doing for years instead of attempting to crimp which can also be troublesome, especially for the DIYer.
I understand the views and potential issues. I've recently fitted an electric smoke alarm, junction boxed from a lighting circuit. It is under the floorboards upstairs, I made sure the boards are not too difficult to remove in the future and marked on them what lies beneath. And when the electrician fitted one elsewhere, he connected it the same way.