As for Battle for Wesnoth... Are the Civilization games bad because there's luck involved? Is X-COM bad because there's luck involved? No. Risk management is a part of these games, as it is in Wesnoth.
I think it also fights the slippery slope effect prevalent in less luck-based strategy games, like Starcraft (Which also has a luck element in that there is a chance to miss units placed in certain locations, but it's a very minor one), where win or loss is often decided the moment one side makes a slight mistake, which creates a small advantage, leading to greater and greater advantages until the side loses. In Wesnoth, mistakes matter - there are ways to exploit them with minimum risk to create advantages that lead to an economy superiority, and sooner or later to victory. But if the disadvantage is small, some smartly thought out high-risk-high-gain bold moves and luck on your side later suddenly YOU'RE in front.
He wasn't saying luck is bad, he was saying too much is bad. If you read his post, he said that winning/losing was random, despite their stats. How can you make a strategy when everything is random? If all units have a 50% chance of killing the other, what is the purpose of having offensive/defensive units? Where's the fun in that. I love details - the kind that can kill you when you miss them. I think he must be wrong about his assessment, but you're also wrong.
How you can make a strategy when "everything is random"? Have you ever even played the game? If not, stating that I'm wrong is a pretty bold move.
The random elements are restricted to the distribution of traits (small boni, like extra HP or slightly faster movement) for certain units upon recruitment, part of the algorithm that determines if an attack hits (highly dependant on terrain type and how well the unit defends on the terrain type, it's rarely a 50% chance), and... um... well, if you choose a random faction or a random leader the result is random too, of course. That's all that's even remotely "random" about the main game.
Unit stats, like HP, XP needed for levelup, special abilities, resistances, defense on the terrain types, movement (how many, across what terrain), attacks (How many different kinds? Ranged or melee? Blade, pierce, impact, fire, cold, arcane? Is the attack poisonous or magical or has it any of the other special attack effects?), the units further up the upgrade tree, recruitment cost... Then of course the map layout doesn't suddenly change at random throughout a match, featuring the same terrain at all time... The result of the mixture of these predermined factors and the randomness - surprise surprise - is a game of strategy, with plenty room for skill, and mistakes or overlooked details.
Some people don't like having to dick around with five different resources, so they prefer Command and Conquer to Age of Empires. Similarly, if you don't like having to consider the possibility of failure for an attack, or the fact that sometimes you will just be too unlucky to win even if you do your best, you won't play Battle for Wesnoth. Claiming it is not a strategy game because it forces you to consider things in your strategy that you'd rather not want to consider, however, would be unfair.