they are a necessary evil I think
but I always take out most of the styling options so that users can only change things like alignment, bold, add links.. maybe type size
I had one client insist on having all the controls and as a result his website looks a mess
but of course the biggest nightmare is the 'paste from word' garbage
TinyMCE now has a 'paste as text' option which is what I tell my users to use
(it has a 'paste from word' option but it doesn't seem effective)
it very much depends on how much work the text is meant to do in terms of layout - ideally I separate out titles as separate entries in the db
I then give users a few pointers on p, br, bold, italic tags so they can fix some basic bugs in the html view
in some ways the hassle helps them appreciate that websites are more complex than they thought