It’s really no more complicated or time consuming than logging into a third-party service and using it to send a message.
What do you mean with third-party-service?
And the security issue remains to be seen. I actually feel pretty secure not having my keys saved and only needing to use them when they’re necessary.
You got to have them saved somewhere - otherwise how do you use them?
I use the existing wallet transfer functions all the time with no issues. Is this new service mainly for noobs? People who don’t know the simple features/functions of the current Steem wallet?
Your software is a "third-party service" (But so is Steemit, Busy and any other front-end, since the blockchain cannot be accessed without the use of such implementations).
I think that by this he meant easily accessible and always "active" (like when you use your browser's password manager to automatically input your password regardless of the user, and using cookies to keep the password wif logged in your session).
But with proper safety measures, this messenger would not be a security risk, I believe, and would instead make it much faster and safer to send and read transactions (especially if real-time notifs were enabled in the future).