I have to agree.
Although some don't mind about losing their postcount or rep, but others might find it hurtful to start from scratch again. Not to mention, like pika2000 said, you might get confused of being a newbie.
And besides, is it so hard to change a name? And if a name change thread is made, you can put a requirement that the person must put on his/her sig what was the old name. And also put a time-waiting period to change name again (For example, at SPPf, you must wait 2 months after a name change to have another).
I AM considering to change my name sometime on the future, but not by making a new account!
Those were my 2 cents.