... and if people are bringing up large amounts of gunk they probably shouldn't be riding in the first place.
Oh so cycling is now only the reserve of the completely fit? -Hasn't it always been?
(I confess though, I'm far from completely fit most of the time - perhaps I should give it up)
So I shouldn't be riding if I have a cold or asthma? What a pile of crap. Correct!
(don't know about the asthma, 20+ years since I had it, but I always rest a heavy cold)
It is a bit of mucus, it may be even a green gob, but it is (or should be) spat into the gutter/grass and is totally biodegradable and natural. It is also natural to expel it through the nearest orifice too than to send it via your whole internal system out the other end.
It might be natural and all that but I still don't want it spat out by the guy in front of me on a clubrun. Even if the big pile of gunk doesn't hit me the spray does and it is foul. There are plenty of things that are natural to the human body but over time we have developed rules/manners/etiquette, call it what you will, to keep offence to others to a minimum.
What riders do solo is their own business but on clubruns a bit of consideration goes a long way. Someone earlier made a good point that if people really need to spit it out then dropping to the back to do it seems a good idea.