Towers are there to defend but they should fall against the focus of DGs. You are there to push the other DGs back so your towers remain where they are. You can even fight under the cover of your tower if you need to defend the tower. This way the tower helps in pushing other DGs back because they should run when you have the upper hand like this.
'DGs are there to fight' is such a meak statement because it could mean anything. DGs could very well fight to defend your towers. He could also fight to destroy enemy towers. In no way should the towers ever take over the job of the DG. Defending is the DG job, the tower is just there to guarantee every team some control of the map in the early game. If you play so poorly that your towers fall very quickly then your playstyle may need some rethinking.
Buffing the towers will just mask your poor playing because they last a bit longer, but in the end the real men will defend the base and push back enemy DGs themselves. Good players do not rely on coocked up settings.