That's not really true. I've only had one and he never had issues. In fact betta queen and transshipper Linda Olson confirmed for me that even long fins have no issues.
I, personally, am not a big fan just because I feel that they are off balance. But I still think they're nice to have around.
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.