I don't think you were playing "wrong." I think that you and your opponent are both playing ultra-aggressively, which is certainly a valid way to play the game.

But if I'm sitting across the table from an Ork opponent with 2 Tellyporta Pads in his HQ, I am probably not going to send my warlord to the first planet very often. And if I do, I'm certainly not going to leave him there, exhausted, for my opponent to keep porting in big guns to smack at my warlord with. The very first opportunity I get (ie, my very first non-Ranged combat turn), I'm probably going to retreat my warlord away from that death-trap.

So, I mean, unless you are using Tellyporta Pad to move your big Orks to any planet (instead of just the first), or if you are playing exhausting your warlord when you commit them to a planet in the Command Phase (instead of arriving at the planet indicated on the dial in the same state as they were in HQ - only the units that come with the warlord exhaust), you aren't playing anything "wrong." But your opponent isn't playing much defense, either.

We can keep going on the "coulda-woulda-shoulda" reasoning there, too. If I'm paying attention, I'm going to see your ready Stingwings, your ready Ambush Platform, and your Drone sitting somewhere on some other unit and understand the potential. I could gamble on you not having the Ion Rifle in your hand, but more likely, I'm just not going to send my warlord to a planet with that much actual (and potential) Ranged ATK strength ready without a really compelling reason (or potential defense).

I would also be happy with a planet victory made easier by an opponent always playing around the potential that I could one-shot their warlord.

I would also be happy with a planet victory made easier by an opponent always playing around the potential that I could one-shot their warlord.

Undoubtedly. But these sorts of interactions do explain why many of us currently see considerably more games won by planet victories than warlord deaths.