I guess this depends on what your definition of "approach" is. For me the MMM approach is about being mindful of the environment, being mindful of consumerism, and making changes to the typical wasteful relationship people have with money in order to save a much larger percentage of our income. This solves the two big problems of time and money that allows us to concentrate on happiness and things that we value.
It's a bit difficult to argue with that approach. People may not wish to follow it, or live life in that way, but the fact we are all on this forum means we are thinking about this stuff and are actively working to make our lives the best that they can be and to spend more of our time away from the rat race. So we are largely bought into this, employing our own version of it, and of course may have been doing this long before MMM was around.
This doesn't mean we have to agree with every single detail or every post on how we go about this. How many people in real life, friends, family etc do we have where we agree with absolutely everything they say? Probably none. I do find the posts about salad and exercise preventing all illness and disability as way off the mark, but it is aligned with the overall chirpy, positive and optimistic outlook that the MMM character provides. Control the 'controllables' is essentially the message there but of course, there is a lot in life that is out of our control.
The 'face punching' phrase I've always interpreted as cartoon style face punching. When someone gets hit five times in a row in a cartoon, there is no pain, no damage inflicted, but it has snapped them out of whatever they were doing beforehand I.e. it's harmless, and a way of providing impact to the writing style. It grabs attention and pulls people in. So I was never really offended at this.
I found this site because I was looking at buying a new car. I was recently mortgage free and had always been scared of investing. I had been to a couple of showrooms and rolled my eyes at some of the sales techniques. Being mortgage free had significantly increased my cashflow but despite this freedom my general frugal mindset prevented me from buying and I thought I would research how to buy a second hand car. (I had only bought one car before and this was brand new). I stumbled across one of MMM's car articles, found the post interesting and then found the page with all the posts from the beginning of time. I quickly realised this was not a site offering advice on how to buy a car but something much broader. One of the first articles I read was the 'Shockingly Simple Math Behind Early Retirement". I appreciate there are other articles containing this subject matter, and that the information was available elsewhere but seeing the table of working years until retirement changed my life. It literally changed my life. Like boom! This information can not be unseen. Whether I like it or not my life is now headed on a different course than it would have been if the table had not been seen.
I continued reading more posts on the site. Although it only felt like a few minutes when I next looked at the clock it was 4am. I had 90 minutes before I had to go to work. I must have been reading the site for in the region of 8 hours straight. I don't think there are very many writers that would make me do that. I've never read a single source like that before with no appreciation of time. There was no rationing out of the articles over the course of a few days or weeks. I just had to keep reading there and then. I appreciate there was a lot of self interest there. I was hooked because of what this approach to life could do for me. I suddenly realised there was a way out of work having been conditioned to accept that we worked until 65. I instantly made a load of changes (I'm single so only me to buy in) and overnight established an 80% savings rate that I have maintained ever since (I found the site in September 2017). The first decision was to cut my mileage and keep my existing car until it was at least 20 years old. So I am still yet to buy a second hand car :-)
Of course that table that got me hooked is based on the 4% rule. As it takes considerable time to reach FIRE I have kept reading and learning. I now see how brilliant that post is at pulling someone in and just making them aware that there actually is a FIRE number. From further research the 4% rule is not something I will be following. I don't disagree with anyone that does want to follow it. Some can be using 4% but have the ability to cut their expenses by 50% while others may only be able to cut by 5% and these are two completely different situations. So what actually does 4% mean? However I don't now disagree with the MMM approach just because I'm going to tailor a withdrawal rate to my own views on asset allocation and my own personal situation here in the UK. I'll do my own research and make decisions accordingly.
I was relatively frugal before my FIRE epiphany but this site has given me the confidence to invest. As a result I will have the opportunity to escape a full time stressful job 20 years early. I am very grateful to this MMM character. I don't see MMM or Pete as a celebrity. I'm not a 'fan' and in all likelihood we will never meet. I may not agree with everything on the main site but this random internet stranger that doesn't even know I exist has significantly impacted my life in a positive way, and not many can achieve something like that. Of course there are some wonderful people on the forums that I have actually got to know and interact directly with. The knowledge I have gained from them now far exceeds what I originally learned from MMM, but nevertheless indirectly introducing me to these people is another reason I have to be grateful to MMM.