If you enjoy the game, go ahead and enjoy the game. Nobody wants you to stop doing so.
But if you really are interested why people hate the game you must understand its over ten year history:
-Warband set certain expectations on what the game is about, how it functions and what features to expect. (Warband released 2010)
-Developement for Bannerlord started about 2012 and was also announced then on the forum.
-A lot of big mod developement stopped around that time because people thought Bannerlord would release eventually (L-O-L)
-Taleworlds did a lot of developement blogs talking about what features they will implement. Before these devblogs I was quite suspicous wether BL will actually be better than WB but these hit exactly the right mark. I got the feeling Taleworlds knew exactly what their game was about and what players wanted.
-Release of the game was announced in 2016 and 2017 subsequently with videos showing the new siege gameplay on youtube.
-Everybody got hyped. -> no release in sight.
-TW got relatively silent -> players got anoyed by that a lot because nobody knew wether the game was around the corner or still years away.
-TW responded by making devlogs again. Most of which completely banine and useless. At that time early access was completely out of the question even though a lot of players demanded it. (I'm not taking sides here. TW tried to appease the audience and wether early access was a good idea is a completely different topic)
-Fast forward to late 2019: TW announces Bannerlord Early Acces. "The game will have bugs but will be mostly feature complete with all of the features present from Warband just some of the new features like the barter system missing"
-Hype
-April 2020: EA release of Bannerlord: A lot of basic Warband features missing. Balance of both combat and campaign completely out of whack. Most features promised before EA missing. Siege pathfinding straight up didn't work. Horrible performance and a lot of bugs. (The letter two are to be expected and I will not criticise TW over them)
-General reaction: It's just EA bro, they will fix / add X eventually! (It will take TW two more years to fix the siege pathfinding from this point lol)
-Summer 2020: TW announces end of EA within a year.
-Also around that time conversation between playerbase could be summarized by: "Can whe have X?", "No X is to complex.", "But X was in Warband!", "-". Anyways, it was around that time it became clear to me that the features missing from BL, which were either present in WB or were announced in pre-EA devlogs, weren't missing because TW was slow but because TW couldn't be bothered to implement them (more on that later).
-The f***ing meantime between 2020 - 2022: Not much of substance has been happening in terms of game mechanics and missing features. But we got new sheep models I guess. The modders on the other hand were already going buisy and proofed that the features TW deemed to be "tO cOMplEx" could be implemented by people in their free time within days.
-Spring 2022: Siege AI is actually fixed, some features have been added and a bit of balancing has been done to some aspects of the game.
-about a week ago: In an interview Armagan (the owner of the company and lead developer of previous M&B titles) said that currently there is not much work going into the PC-version of Bannerlord since the game is pretty much finished*, however porting Bannerlord to console proves to be a hard task. *He actually just stated that finishing the game and porting it to console is being done at the moment in parallel. That porting Bannerlord to console makes up most of the workload at the moment is an assumption on my side. However I think it is a sound one.
This proves what a lot of us were already thinking: TW doesn't care about what PC players want. They espacially don't care what Warband veterans want. They already got our money. What they care about is getting the next bunch of cash by releasing the game for console, on which the more nuanced and complex features either prominent in Warband or promised in earlier devlogs wouldn't work well anyways and thus are "too complex".
Adding insult to injury TW never cleared us up about how their vision of the game changed. They never told us which featues they promised we could expect and which not. They never gave us a specific roadmap of whats to come and what not. And they didn't tell us that in fact they are not working on improving the game but instead making a console port while still keeping everything under the veil of "Early Access" so criticism could just be done away with saying: "well, it is still not done yet. It is in Early Access afterall!".
People stuck loyally for over ten years with Taleworlds just to get stripped of money and then stabbed in the back.