I disagree with this to some extent. People often exaggerate about rushes in these games. I feel like rushes should have a chance to succeed. In most other games a rush is a risky business. It is usually successful towards low elo player however if the player knows how to defend then the rush leaves the attacker with a huge economic disadvantage. In fact as you climb up the elo rushes become less frequent and people tend to raid instead with small amount of units.
The problem is that 0ad tcs are definitely OP and ruin a big aspect of the game, both rushes are not viable because of the sheer disadvantage of the attacker, nor raids with smaller forces if the player keeps the units close to their TC
One is that they shoot without any garrisoned unit, they have massive range and they deal a ton of damage. In AoE2 for example if you want to kill the enemy explorer you have to carefully micro your vills inside the tc losing some resource gathering time, and even then it is not a guaranteed kill. In 0AD if your explorer stumbles upon an enemy TC is dead 99% of the times with no action required by the defending player. This also hinders scouting which is very important to plan a counter to your enemy strategy (altough 0AD counters or, more accurately, lack of them deserve a whole other discussion)
I think a good starting change would be to change to make the TC do not shoot any arrow if no units are garrisoned inside, and generally nerf their range.
Another thing that makes raiding unprofitable in 0AD is the cheap costs of units and the speed in which units are produced. In 0AD a village kill is most of the time not a big deal, another one will be spawning soon, and if the player has the tech that lets the houses spawn new villagers this is even less meaningful. This should also be tweaked if TCs are to be nerfed, both villagers and military units should take more time to train and cost more resources. That way an unsuccessful rush can be a fatal mistake because of the amount of resources invested in it.