I don't usually use the word "should," especially when it comes to webcomics. Whenever I hear advice about webcomics in the form of "you should do this," I question it. Why do we make comics on the web, other than to let go of the externally imposed standards of companies, publishers, and society in general, and do whatever the heck we want to?
I've noticed that our society has a particularly strong stigma against the idea of quitting something, and I think the strength of the stigma is harmful to people's overall productivity and happiness. We value hard work and dedication - pushing through whatever you're doing, finishing what you started. But I think something we don't value enough is stepping back and evaluating whether or not your effort is actually going somewhere positive. I think one of the most valuable things someone can do is give up on something that they've already put time and effort into, because they realize that it isn't working for them.
This started out being about webcomics, but I guess it could apply to a lot of things. In business, people often have to try several ideas and drop them before they come up with something that works. So if your comic becomes one of those over 50% that die within the first 6 months (I don't know the statistics exactly), consider it an important stepping stone. You learned something about what you don't want, you got experience, and you had enough insight to know that you wanted to give it up and move on to things that are more important to you. Or maybe your circumstances were more drastic than that, I don't know.
I'm not trying to discourage anyone from making a comic they love. I just want you to ask yourself, if you are continuing, then why? Because you feel some vague obligation to keep slogging through it, or because you want to? And I want to acknowledge the value in quitting something. What may look like a failed project may be an important step to great success.