Drilling is absolutely important for BJJ. People don't like drilling much due to 1) lack of discipline, Just wanting to work on what they want or 2) don't have a desire to improve.
They rationalize this by saying it's not fun, or they dislike drilling something they'll never use. But if you have a good instructor who knows what they're doing, not all of what you're doing will be fun. As a blue belt/new purple belt, I thought I knew what I needed to do to get better and what I wanted to work on. Until one day my instructor made us drill flying triangle and flying armbars for 2 weeks and nothing else. Training was 2 hrs long, we literally showed up and drilled flying armbars/triangles for an hour then rolled non stop for the next hour. I thought, I will never use this stuff and it's dangerous, I'm wasting my time drilling this. For the next few competitions and even years later, I've hit flying armbars/triangles without even realizing I wanted to do them and finished with them in competition due to muscle memory from drilling them so much. Even up to brown belt, most practitioners that don't drill nor show up for warm up have shitty movement. They suck at moving their body efficiently and this makes it so hard for them to learn new things that involve movements out of their element. I get purple brown and even black belts that come to my school to train its me and their movement is terrible and something as simple as getup to the knees suffers, they can't perform them well.
When I was still a brown belt, much less a purple belt, did I know what I needed to do to get better? I thought I did but my instructor put me in my place quickly and hammered down new concepts and made me drill that stuff till it sucked. He's shown me many things that I thought would never translate to my game and made them into strong A game material for me making me drill a lot and didn't let me just show up and roll all the time. Just like when you attend college, you don't tell the professor what you think needs to be covered so you can learn and improve, you shut the f**k up and listen and practice what they present you. You don't show up to BJJ class and tell the instructor what you need to do to improve.
There's nothing wrong with wanting to show up and just rolling all the time, but don't hide that behind "I want to improve." If you want to improve, you roll a lot but you drill a ton also. If You don't want to drill because its boring, again that's completely fine and nothing is wrong with that and you do want to "improve" but You just aren't willing to do what is necessary to improve.
Reading most of these posts here, it seems to me many of you are just shitty students whining. Not all and I don't know your individual situations, but what comes off from being written in the posts it seems that way. I can also understand if you have an instructor that is just checked out and doesn't give a shit what you guys drill, that really is an unfortunate situation in those cases.
Nobody in any other combat sports just show up and "spar" all the time. In BJJ it seems to be the only martial art where people just want to "roll" or spar. imagine doing boxing, muay thai, mma, etc and just showing up and sparring every session. That would suck and you'd improve extremely slow. Even wrestling you don't show up and go live every session, so much drilling is involved.
Just my rant and observations as an instructor