It really depends on 3 things; After so many failed attempts are you offered a sign-in using your Google ID? If so do you have a network connection to the device? If you are not being offered the Google sign-in option, Yes you will have to Factory/Hard reset. Or if you are but don't have an active network connection, either WiFi or Data, Yes you will have to Factory/Hard reset. I heard that Some carriers used to unlock them for customers, but the last few I've seen post this question that did talk to or go see their carriers were told to reset. You could try that option and see if these were rare events or have become the norm...?
Utilize Android Device Manager. If you know the Gmail email address and password, google Android Device Manager, log in with your Gmail Account. You can GPS track it, remote wipe it and send a new password to your phone, which allows you to open your phone without having to wipe it. It's a life saver, if you remember your Gmail email address and password.