Thunderer has access to many kirks. The Sovereign, the Thunderer, the Dauntless. He didn't have to pay for them. Other people have to, they can't bring their battleships depending on the situation. What you suggest it people making anti-snub battleships for the case of them being needed in case of them getting attacked by snubs!?
[Insert your favourite Tom Cruise laughter meme here]
That's not how battleships work. You don't make a battleship and equip it with anti-snub loadout IN CASE OF THEM ATTACKING THE CAPITAL. Why the hell would you even log that? Only for the very rare team fights where one side sends in more snubs against the side that has more battleships? Since when do people do that? They'd simply switch to snubs as well. No, battleships are to be used to cause damage in great amounts. Usually against other capitals and PoBs, but less often against cruisers because of in this thread mentioned issues and almost never against gunboats or snubs. Anti-snub capitals are either something an absolute lolwut would log to get cheap blues or something you log in pre-planned event fights where that is a legit role. Otherwise, brining a capital with AS loadout would be the biggest waste both of money and potential in a fight. That is how the community currently works. It's like saying the pope could technically have intercourse.