I'm afraid I cannot agree on your first point. In the current build, a Dragon is flat-out cheaper than a Juggernaut, in both resources and time. A Dragon can die twice (25 Recruits each respawn cost) for less Recruits than the cost of one Juggernaut (52 Recruits), and less time (instant respawn versus whatever build time a Juggernaut has, but I'm sure it's like 8 seconds at least). Claiming the Dragon is more expensive (and then in the next sentence saying it's a "a novelty that does nothing") is objectively wrong.
I can, however agree that the Dragon in campaign mode - without upgrades - is indeed a novelty that isn't really that useful. We'll have to see after the upcoming patch how things change.