It hasn't been a problem thus far, but we'll keep an eye on it.
As for why it's like it is....
The Terms Of Service (viewtopic.php?f=8&t=2
) actively encourage people to self-moderate and sometimes what seemed like an appropriate or decent comment at the time, might seem tasteless, tactless, irrelevant or distracting when viewed later with fresh eyes. We like to put trust in our members that they will do the right thing and take various factors into account when editing or deleting their posts, such as the issue of continuity which you raise here. To empower people to self-moderate as they think is best, and take responsibility for their speech, they need to be able to edit their posts.
“I hope, Anuruddha, that you are all living in concord, with mutual appreciation, without disputing, blending like milk and water, viewing each other with kindly eyes.” (MN 31)
What is the final conviction that comes when radical attention is razor-edge sharp? That the object of the mind is mind-made (manomaya). (Ven. Ñāṇananda)
"If you have always believed that everyone should play by the same rules and be judged by the same standards, that would have gotten you labeled a radical 50 years ago, a liberal 25 years ago and a racist today." (Thomas Sowell)