I've seen many Accounts with negative trust on this forum. When I checked I discovered their offence was the use of Multiple Accounts.
Having multiple accounts is not an offense by itself on this forum. If you encounter a negative trust rating with such an explanation, it is a sign of misuse of the trust system. (I honestly didn't notice such trust ratings from DT members based on multiaccounting. Perhaps you have some example to show?)
My question is
Why do people use Multiple Accounts?
Does it mean that one Account is not enough to post on this forum?
People use multiple accounts on online forums for different reasons, and there is no one-size-fits-all explanation. Some use it to maintain anonymity, others to express varying opinions, and some just for the enjoyment of having multiple online identities. The motivations behind this usage can vary greatly from person to person.