They are quite good for their dice since they manage to successfully operate that for years and we cannot expect that their sportsbook will run smooth since it's new in the first place provably those flaws encountered will be fix and once many users will report the bugs or others if they see it for sure the job of the dev to make the sportsbook became better will be more easy.
I am not sure many people reporting or not and either many people will report or not. Because as they have lack of feature people will stay away from paying sports. As no player there are too many game which cant stay on in play, they goes away from start soon. That means they have only few players on their sportsbook.
Sportsbook at Bitsler is still considered as a new thing, no doubt if there are still many things to improve/update/add.
There is something what we usually call by "process", there is no instant perfect sites. Rome is not built in a day...
Bitsler wont wait till there are many reports or requests, they will work on it to make it better obviously as what they do with the casino games.
Absolutely no one is forcing others to play at Bitsler, its all about preferences. Even if Bitsler has all features on the sportsbook, it does not mean that they will have many players.
On the contrary, having less feature does not mean that Bitsler will have few players only.