Why is it that 2 different people can have the same name?
because it is Name@forumhandle. in my opinion it is more realistic. for example your name is john in real life, but you are not the only john, there are other people who have the same name john as you. it's the same idea here. the only thing different is the forumhandle. this also lets you have the name that you want, and it doesn't block people.
I'll admit, I have a character calles Picard, but only for the purpose of Captain Picard Day and Ten Forward activities. As far as I know, I've actually got a unique name for one of my characters, Iaeger (spelled with a capital "i" and not l). Ya can search it and mine will be the only one to come up, unless someone has went with the name recently.
It is a compromise because of the fact that we run on a single shard model. Requiring unique character names means that people are likely to get frustrated if "their name" is taken immediately after launch (especially given how active the RP community is). The same is true of ship names. We really wanted to avoid seeing names like "x-x-Picard-x-x" or other similarly unfortunate schemes. It isn't without problems, but we feel the benefits outweigh the downsides.