What's with the David vs Goliath complex? You think the Albanians were easy to keep a lid on? You think the Bulgarians were pushovers? You think the Serbs and Croats didn't put up a fight? You think the Hungarians just bend over? The Turks had plenty of experience subduing people who didn't like their authority.
Fact is, by the early 16th century the Ottomans had all they really needed from us. We paid an immense tribute, we gave them military support when they asked for it, we let them use our territory to invade Transylvania or Poland, they strangled us strategically and economically through the territory they took from us, and our most powerful boyars were bidding for the thrones in Constantinople (and this was before the Phanariotes). In the nearly 2 centuries between Petru Rares' overthrow and the Phanariotes there were only a handful of serious attempts to shake off Turkish vassalage, Michael the Brave's being the most notable. We didn't survive because we were natural born killers and the Turks shook in their boots upon hearing of us, we survived because whatever local boyar or occasional foreigner gained the Wallachian or Moldavian crown could exploit the land more thoroughly for the Porte (and still keep something on the side) than the Turks themselves could. (Michael's raising of taxes to fight the Ottomans rather than placate them might be unique for this time period.) If we didn't inhabit some of the most fertile soil in Europe that arrangement would've never worked and we would've been annexed after the first time we failed to overthrow Ottoman control. It's not out of patriotism and warrior ethos that the population of that rich land was dropping even before the Phanariotes.
As for the Phanariotes, I don't think even you would argue that we were the scourge of the Empire then. The Phanariote period is when the Romanian people made the decisive move from a nation of warriors who fled to the woods to organize resistance against invaders to a nation of miserable peasants living half-underground who fled to the woods to escape the tax-man.