As long as you have done your homework and selected a reputable,
trust worthy hosting company, there is no need or reason to have
multiple accounts. IMO anyway.
Sure, shit happen, all the time in fact. The server you're hosting
your sites on may crash, or something minor may happen, resulting
in a short period of downtime, but, that can happen no matter how
many sites and how many accounts you have.
I have well over a few dozen sites in all and they are ALL hosted on
one account. I do not do this to primarily to save money, however,
that is a nice perk. BUT, I have also been fortunate enough to not
have suffered any considerable downtime in the last 7 years or so.
In fact, I can only really recall 3 instances, and one that I know of
for sure, was due to system maintenance and my hosting provider
let us know well in advance so we could plan accordingly.
If anything ever happens to the server, sure, all my sites go down,
however, since I use one main (global) order/purchase system any
ways, if that one site goes down, none of my sites will function as
they should anyways, so, for me personally, its ALL OR NOTHING!
Regardless of how many accounts you have and for whatever reason,
I would always strongly suggest doing your own weekly (daily if ever
necessary) backups to ensure you always have up to date copies of
all your sites content.
