WHY is Yahoo revamping the email program? I HATE the new Beta version. Haven't the programmers USED it?

The 'NEW" and 'improved' addition sucks! You have to go completely down to switch from left to right to read an email. You have to go to top to delete or move where old program had it always accessible. Annoying to keep going up and down every little bit. Don't the programmers USE the program before they put it out there? PLEASE, don't delete the old program. Yahoo.com is the ONLY email program I use. I have never had problems til this latest version came online. I try to use it everyday but it is so annoying I go back to old version. Are you still going to force this on us before you get the bugs worked out? NOT FAIR! If something isn't broke WHY fix it?????