I don't think they meant health problems. HMs in general are difficult because of their fins. Spawning them is a hit or miss, maintaining them in perfect condition is difficult, and raising them to have a 180 degree caudal spread is even more difficult. Take a lot of work.
Who am I? Well I am a Junior Member of the International Betta Congress and a breeder of white HMPKs, red dragon HMPKs, black/red dragon HMPKs, metallic multi HMPKs, blue masked HMPKs, and now multi color HMs. Soon to add black HMs. I will be showing in New Breeder class in fall of 2012.