One other thing, which was already stated, but needs to be reinforced, is that the plastic/vinyl gutters lose their plasticizers over the years due to the harmfull UV rays of the sun.
They become very brittle and often times, just shatter when you lean a ladder on them at the proper angle.
The sectional splice joit pieces create multiple trough areas in the gutter, where small debris gets hung up on and creates a backlog of additional accumulated debris.
But, more so than the function, is the inherent lack of personal safety that occurs, due to needing to set up a ladder in a more vertical position than intended, so as to not disperse too much body weight against the outer lip of the gutter, which increases the likelyhood that someon could slide and slip from their ladder.
Ed