No. Yes. Kinda.
In general a player might run into too many looters get hit by rocks, go "This sucks", re-set the game and just not do that again.
However many people have complained over the last year about this and I think it's a valid complaint.
I question "what is the point of looters"? When you dump a bunch of units on the map the devs should be considering why?
In warband looters where the weakest of the weak and served as fodder for a fresh player and recruits. They had low hp, were slow, thier rocks were just effective enough to teach the player they need to move thier butt a bit. Looters served this "warm up" function well and it could even be a problem of not finding enough early game when you wanted some! Getting the "hunt the looters" quest to spawn looters was a big juicy treat just for the player!
In bannerlord however it feels very unbalanced as looters and other low tier units are fast and accurate with thier stones and have just as much HP as anything else, needing about 4 body shots from a steppe or hunting bow to kill them and are pretty inconvenient for skilling up on (alone) because of this. Sure the same is true for your recruits and have about 2/3 the amount of them you should easily over power and rout looters. But sometimes bannerlord dumps large amounts of looters and no small parties at the start of the game and I wonder why? It could be they are immediately being captured by peasants, then freed by other looters and making these large parties.
I guess to me I look at everything as a resource and I don't like seeing "too many" looters or for the looters to be "too much" effort to defeat as the gain in doing so is very petty, but I feel compelled to 'take' the resources the game presents me. So you get this strangely phrased complaint of "I killed 30 looters solo and I hated it, could you give them less rocks or less range please?"
In a vacuum, no, but when examined with context they showcase a lot of the combat-related issues which plague Bannerlord as a whole.
Issues such as unbalanced damage calculation, the impact (or lack thereof) of armor vs. attacks, the speed and accuracy of ranged weapons, the supremacy of ranged units in general, # of missiles ranged units receive, bandit party size on campaign map vs. player character level and party size, too much parity between units of all tiers (*Important*), and troop quantity vs. quality disparities.
As @Ananda_The_Destroyer stated above, looters served as a first test for players in Warband. They were pretty manageable, with only the most inexperienced or clueless players falling victim to them in battle. Looters served not only as a first test, but also as a clear benchmark of what constituted as "weak" within the Warband unit power-scaling. While potentially deadly for a poorly equipped player or Tier 1-2 units, they essentially became cannon fodder for anything greater. This is due to the effective and successful troop tier power scaling present in Warband -which was made possible because armor actually worked.
Compare this with Bannerlord, where there is much more parity -honestly, too much, between the troop tiers. This means that units like looters punch well above their weight class in terms of damage output vs. enemies. This is why looters and low-tier fodder are able to significantly damage/kill elite troops with alarming success. In Warband, there was an actual distinction between high-tier units and low-tier, which incentivized the player to build a well-trained, well-equipped army. In Bannerlord however, the game is simply a matter of collecting as many archers/crossbows as possible with some tertiary infantry and cav troops to fill the role of being a distraction. Troop experience/equipment doesn't matter, only sheer numbers and ranged units do. This is why people are derogatively calling Bannerlord a grindy warfare simulator.
And lastly, this also means that looters simply aren't fun to fight. Considering how armor is useless and the sheer MLB pitcher-like accuracy looters possess with their rocks, it's nightmare to try and actively fight them in combat as a player. And that is a big deal, active vs. passive gameplay. No one wants to fight looters of all units with F1-F1, simply standing around and waiting as your archers shoot them down. Standing and waiting simulator, real fun. But in many cases, it's the only safe viable option. I remember how frustrating it was doing all I could to dodge their rocks; zig-zagging, spinning, crouching -to no avail. They were able to hit me effortlessly (even from considerable range) every time. Plus, the damage those rocks did was foolishly absurd. Even mounted on horseback, the looters were deadeyes with their rocks. Taking an angle, full gallop -didn't matter, got nailed anyways.
So it's not so much the looters are bad, it's just the game is bad. The game mechanics are set up to encourage passive gameplay as opposed to active gameplay, and looters are just one example of this -other examples include how players conduct their wars, build their influence/armies, and kingdom/clan diplomacy. It's a waiting simulator. Too much passive gameplay is a problem, because with not enough active gameplay people with get bored and move on. Too much passive gameplay is not good for the longevity of your game, and Bannerlord is one of the most passive games I have played.
@Hans, yeah, the way Armor is implemented is actually a big problem. It should be about, what, twice as effective as it is? Unfortunately, TaleWolds uses an asymptotic function, so 100 Armor = 100% protection, so you have to bust out the slide rule to do any armor adjustment.