I am not saying that we wouldn't kill a couple but in the end 5 titans are way easier to replace than 300 dreads. The titan pilots would probably be in a new ship in the next couple days but the dread pilots might have to wait weeks. I still think it's a viable strategy to suicide dreads but only if you can do it on your own terms, forming up a 250 men dread fleet would bring every supercap alliance to the fight and it is impossible to do it unnoticed.
The argument that it will discourage people from bringing titans is flawed because of the bottomless pockets of all tech holding entities and the fact that people love killmails and 300 dreads is a lot of killmails. I am pretty sure that any titan lost in such a fight would be replaced and that would only encourage people to bring their titan.