There is truth in some of what they are saying but I would avoid giving percentages in that it is impossible to prove correct. I’d stick with generalizations.
An example of the facts which don’t jive with me. When I used to do weddings, my clients didn’t feel they should have to spend more or think they should have put more effort into the music at the reception. How do I know, for many, I also did other events for the families. For the first 15 years, everything wedding-related was all referral, no advertising, and I was busy. One family pulled me back from not doing receptions to do a wedding reception a couple of years ago for another relative. And I am sure there are plenty of other DJs who do a great job too.
It is the brides who cut corners, do it themselves, or hire unqualified DJs to whom these statements would apply. In many cases, they might not be able to, want to, or care what happens as they deem it not important.
I did do lots of the general cookie-cutter weddings but as competition increased I started doing more of the non-standard weddings like karaoke weddings receptions, receptions where they chose all the music played, and a reception where most of the music was from Pulp Fiction. One of the funniest was a Middle Eastern & Spanish wedding reception in NYC. I was hired to play the Spanish music and the band was to do the Middle Eastern music and intros in Spanish and some other language. Of course, the band was late. Then maître D and a couple of people came over to me speaking in Spanish to see if I could do the intros. As I look at them like a deer in headlights, because I don’t speak Spanish. Now that was funny as hell, we waited for the band to arrive.
One reception that proves the point on how important music is. I had a wedding for just 20 people at a private venue of some world-class chef. Music was an afterthought, they weren’t going to have a DJ but figured they needed someone to play the music for the ceremony. The entertainment was supposed to be the food. I was given a list of exactly what music to play, I just had control over what order to play it in. Well, these people danced like there was no tomorrow, and a couple of times I didn’t hear the dinner bell and had to face one pissed-off chef. There was more to the story but when it was over no one was talking about the food. I made it home in record time because I was starving. Never saw so little food served, large plates, super small servings. Why I don’t know and why were there flowers & weeds in my salad?