Groomers use many different tools....
I don't have an industrial dremel, I have a little cordless mini one, much less powerful than the industrial one my husband has. Although I have used the bigger one on my larger dog.
I can tell you there are no chunks flying off when done correctly. You don't have to use a dremel if you don't want to but for me and my dogs it works wonderfully and I have been doing it for many years now and haven't had a problem. Nor have I nicked a quick, which when using the guillotine type I have.
I worked in a grooming shop for a while and often we just tipped the nails with guillotine clippers but with dogs that had really long nails it was easier to use the dremel and we could get the nails much shorter which made the client happy!
I don't see the harm if you are using it properly and learn how to use it properly, many people are doing it and it works for them. Nobody said you have to use it! I have friends that won't even cut thier own dogs nails and do go to a groomer or to me!