I used to be mad too at the slow process,but i relaised its a good way of sorting serious users!
While many here on Steemit like to complain about the slow sign up process, I myself am glad that new registrations are carefully considered from being from fake users or emails.
The process of approval taking time makes Steemit more legitimate(as it doesn't approve fake emails of just one hour or day old!)
It is also a good way to test people's patience lol!
It is a sorting mechanism of only getting serious people here.
There are times i have had to help people i sign up in Uganda thoroughly check their emails and even sometimes the emails are sent in spam!
I will try this steeminvite service though.