For that matter, his weenie of an assistant also looks almost inhumanly scrawny and small.
I don't think these things are accidents. Mar's company clearly has access to cloning technology as revealed by Plank's visit to the man he killed earlier. I think what we're seeing is a pair of men who have been around for a long while. Copy of a copy syndrome would tend to make each generation of clone more error-riddled than the previous one. Selenis has been on top of the curve with clones that are fairly close to the original. These two may have been opting towards mental and emotional stability, or perhaps lack the means to evaluate new clones altogether. They must be getting pretty desperate to find better technology.
A second comment - in our current, real world, philanthropic pursuits from aging people account for an incredible amount of good for our society. Warren Buffet and Bill Gates are just recent examples of this. Rockefeller funded hundreds of libraries, despite a reputation for being nasty to his competitors and employees. Jimmy Carter is probably more famous now for Habitat for Humanity than for his presidency. It is fitting by comparison that the quest for immortality is a vile, destructive thing.