Low landcounts look like a chronic issue - how come?

Based on precons, WotC suggests 38 to 40 lands. I myself run 37, 36, no less than 35. I always run way more cards with mana value 2 than 3. But I saw some lists with an average mana value of 3+ running 33 lands. Even with those double-sided land/spells, that looks like self-sabotage. Lands that enter tapped are a significant drawback, especially when your oppone t plays only untapped lands and straight on curve. Is it only me or are decks with low landcount ever more present on moxfield etc? Do they really work? And who brought that up when the mothership advocates for about 39 lands?