I know, how dare anyone consider their audience preferences in combination with their own when determining content to upload amirite? There is an incredible holier than though complex that comes people on community forums as though they are more noble because they do it for the artistic integrity or whatever reason. If that was the reason, none of you would spend the extra added time and effort to put a video on the internet for others to watch.
The fact of the matter is that every YouTuber defines themselves by their audience. Some are happier with a smaller audience than others but if you got ZERO views, you wouldn’t keep uploading for any appreciable length of time, no matter who you are. Don’t deny it because you’d be lying. You’d probably keep playing the same games or doing the same activities but putting the time into recording, editing, encoding and uploading isn’t worth doing if people aren’t watching. Yes it’s important to do content that you enjoy and have fun doing. Yes someone doing a game they don’t like just for views because it’s popular is obvious to the viewer and bad. However if the choice is between two games you enjoy and one would get better views, the decision is obvious on which to put extra editing effort into. Further to that if the choice is between just playing the game instead of going through all of the work of making a video presentable for YouTube only a handful of people are going to watch, the return value whether monetary or just personal satisfaction drops through the floor.
If the Let’s Play is getting terrible views compared to other series on your channel, then perhaps focusing more effort on the other series is a better use of your time. You do have to ask the question, are you having fun with it anymore. And it’s a valid question to ask yourself if you’d have more fun doing a completely different series. For myself personally, I can have a great deal of enjoyment from a wide range of gaming related topics and video types. The ones I’m going to spend the time putting on the Tube are the ones which net the greatest potential. The others, I’m just going to play and not tell anyone about.