It's like use the outhouse, so as not to stink up the place. We'll dig a new pit when the current one overflows and the becomes unbareable. It's much easier to coverup the old outhouse then to clean it up.
I think Nordeus think we are wee 10 year olds who are as thick as sh@t and we can't see why they have a vent thread. No amount of covering up will hide just how much Nordeus are a joke of a company.