Twitter Makes TweetDeck More 'Secure'

Having recently logged on to my Tweetdeck account, a web-based app that allows direct tweeting to any number of Twitter accounts, I was informed that I had to move my login from a unique Tweetdeck account to one of my Twitter accounts before the 31st March. This apparently is done in the name of making things more secure.

Now forgive me if I think this is a trifle disingenuous. At the moment, my Tweetdeck account accesses both my personal account, and the account for Europoint Communications. By linking my Tweetdeck account to one of my Twitter accounts, not only will anyone hacking my Tweetdeck account be able to access and tweet from both accounts (which to be honest would always have been the case), but they will be able to log in to my personal Twitter account and access the other.

This means that, where before, anybody attempting to hack either of my Twitter accounts or Tweetdeck, would need three different logins, one for each account, now they only need one to gain full access.

Please tell me Twitter, how is that in anyway more secure?