All personal opinion without knowing a thing of what you're talking about.
You cannot judge that of which you do not play, simple as that.
Yea, and I forgot to mention that the realm of 5, 6, 7, 8, and 9 string basses is that of musical genres such as jazz, funk, etc. You RARELY see anything above a 5-string in rock and metal bands.
True, right now I know nothing about bass so I'll take that comment back. Also at first I think a four string would be easier for me to learn that say an 8 string.