It is my experience that DIY is popular among many, be it as a hobby or as a profession. And of course, there is no shortage of evidence on the Internet to support such a claim; discussions about how to obtain the best results for specific situations are common on blog sites and elsewhere. And I am sure that freelance contractors and employees from hardware stores like Wickes and Great Mills will always be keen to lend their opinions and show examples – particularly when DIY is such a multi-faceted interest.
That said, however, it is hardly the case that all branches of DIY recognise roughly equal numbers of people with the right skills to boast therein. For example, I believe that it is a fair bit that relatively few people know how to do “roofing” properly. Many (like myself) are unable to say a great deal about it other than the things which are blatantly obvious to all: roofs consist of tiles (usually heavy duty ceramic); the best roofing jobs are the ones that look even and tidy and, more importantly, are ones where the tiles assembly is strong and stable; the tiles should not move around too much if at all (especially if it is somewhat likely that one may appear on that roof!); etc.
You may have deduced from the comments of the second paragraph that poor roofing jobs can give rise to hazards – but that is not the only thing that has often made people point their fingers at those who call themselves roofers when they have in fact done a poor job. For example, if rain gets through, it can lead to a situation that is not only unattractive and uncomfortable; in the worst cases it may lead to other problems – problems do not necessarily avoid being classified as worthy of urgent concern.
And that is an introduction to the truth of roofing, if not equally an introduction to the roofing industry. It is all very well to seek the services of a professional roofer (compare quotes), but you should be on your guard against rogue builders ignorant of the professional standards that are. Professional companies should be willing to check up on their work as part of good customer service, as well as be able to comment readily on the topics of warranty and insurance, as well as property protection (protecting your home from debris and waste).