In other words, the purpose of a heavy tank is to drive around the map long after the game should have ended.
That's not a good reason to build a unit, IMO.
You can make the same argument about nuclear bombers.
If you're dominating the map, and want to have a bit of fun dropping (expensive) bombs on (helpless) targets.
Sure, go ahead, knock yourself out.
But that's not what people need to know when they ask "should I build this or that".
They need to know how to survive, how to win a tough war, how to be more effective.
In this context, telling someone to build heavy tanks is just bad advice.
Players who follow this advice will be easily beaten by players who build more practical units.
That's not a good reason to build a unit, IMO.
You can make the same argument about nuclear bombers.
If you're dominating the map, and want to have a bit of fun dropping (expensive) bombs on (helpless) targets.
Sure, go ahead, knock yourself out.
But that's not what people need to know when they ask "should I build this or that".
They need to know how to survive, how to win a tough war, how to be more effective.
In this context, telling someone to build heavy tanks is just bad advice.
Players who follow this advice will be easily beaten by players who build more practical units.