I read Dr. Maskin book on dry eye (which was published last year) and he didn't even include IPL as a treatment for MGD on his list. The only mention to IPL was to say something like "I get people that has gotten 12 IPLs without any improvements". So, the book it's kind of the longest ad for MG probing out there, it's only helpful in making you believe probing it's a cure, and everything else a scam.

Apart from that, I think Maskin wants his treatment to be the standard (he has stated a lot of times that everyone with MGD should get probing) but the truth is that his treatment never truly spread because of the growth of IPL and Lipiflow entering the market in 2012. Nowadays few clinics add probing to their in-office treatments (because it's very difficult for them to do it without risking provoking irreparable damage to the glands, while IPL and Lipiflow have almost 0% risk), and in fact some are removing it due to the reasons I've just mentioned.

To sum up, just Maskin's ego.