it all makes perfect sense
Take a good browser, first choice of many people who knows a bit about computers. Than make it look and behave like a phone browser with hamburger menu, knowing it's intended for desktop use with a mouse. Than make it refuse addons because they are dangerous, even though the user knows the risk and wants (needs) them. Than kill the parent e-mail client.
What do you expect ?
I moved to Seamonkey.