Tim's point is that if criminals are going to get guns anyway (legally or not), law-abiding citizens should be able to legally obtain guns so that they can protect themselves from criminals with guns.
His fear is a home invasion scenario in which an armed assailant enters the home and the home owner can do nothing to stop the assailant from taking property, assaulting the residents of the home, etc. In a situation like that, you bet anyone would wish that they could meet the force with force. Is it likely that someone is going to break into Tim's home and pop a cap in his ass? Not really, but I can't blame the man for wanting to be prepared.
Does that protection actually work though? Are there less people hurt/killed during burglaries in the US than in countries where people don't have guns for protection? Are more people saved by having a gun than are killed or injured accidentally by them, or killed or injured because the fact they had a gun escalated the situation and got them shot/attacked by the criminal before they could use it, or killed or injured because criminals go in more aggressively in the first place because they know their victim might be armed? I don't know the statistics but as far as I know I don't think less people per total population in the US are burgled or hurt or killed by criminals than in European countries where people don't have guns. Unless it's actually causing less burglaries or less people to be hurt or killed during burglaries what's the point? I can't imagine wanted to go to the extreme of having a deadly weapon in the house without at least knowing that statistically it might be beneficial.