I hate the term "weak draft" when it relates to a position, especially offensive line.
Mark Tuinei was an undrafted defensive tackle. Nate Newton was an undrafted player from the USFL. Mark Stepnoski was a 3rd round pick. Kevin Gogan was a 8th round pick. Erik Williams was a 3rd round pick.
There are ALWAYS great linemen in every draft.
So you trust a rookie lineman who you havent even drafted yet to block any combination of Khalil Mack, Bruce Irvin, Justin Houston, Tamba Hali, Dee Ford, Joey Bosa, Melvin Ingram and probably even Aldon Smith and keep your oft injured QB upright? That wont end well.
And thats assuming they actually pick an OT in the draft. Just because thats there biggest need doesnt mean that is what they draft. Frankly Romo is far better off with the Cheifs or Texans.