I think you have hit it on the head, shanma when you say that if people post politely and are respectful of others, that is OK, and that is how Gransnet is. Most deletions are for spam, but some are for impolite and disrepectful posts - and a suprisingly large proportion of those are from posters whose names have never been seen before. There is an increase in the number of wind-up posts at half term and the start of school holidays, for some reason - it reminds me of girls I knew at school who got together to concoct a fake letter to a magazine agony aunt.
Don't be put off - most of what is posted is warm and friendly, and there is a lot of support and humour.
All comments are valid, but if someone were to move into a new home and begin their friendship with the neighbours by telling them that the trees in their gardens would have to be cut down, that everyone here should stop speaking a strange language that they don't understand, and it is dreadful that the nice young man they saw looking for work was sent away with a flea in his ear, then they might find their welcome was a bit muted.
The trees may indeed have grown taller than expected and could do with a trim, but they were there when they viewed the house. Making friends first and then mentioning it might be more effective. It is up to a newcomer to pick up the strange language - which is not being used to exclude. The young man who seemed so nice may have been a criminal well-known to the neighbours and not trusted around.
New GN members are sometimes confused by abbreviations, like DD for dear/dratted daughter. These are commonly used online and are convenient shortenings - like TV or EU. No-one has to use them, but recognising them when someone else uses them is very soon picked up, just as new terms of any kind are picked up in conversation.
The site is a magnet for advertising spam and scammers, which are deleted whenever they are noticed, as are posts from people who have clearly only joined to post things that are deliberately hurtful or misleading. Don't think that I am accusing you of that, but "the neighbours" have been bitten a few times, and are a bit cautious of posts that appear to be instantly critical.