Personally, I think if it's an after thought it doesn't work. Now, if you have love as a main part of it then it can work well.
In my series I have a few love stories woven within and they deal with real life topics like cheating, sexuality, sexual appearance (cross dressing, drag, non-binary are good examples), number of partners (monogamous, poly, FWB, flings/hookups), and societal/cultural norms/expectations (lifestyle choices, arranged, connivence, etc). These stories and situations would not work well if my comic were more light hearted and these were an afterthought. My comic is serious, so it lends itself better to real and messy love.
Yes, love stories do help achieve a broader market, but if it is disingenuous you will lose the main core of readers. Always write for your fanbase. If it happens to have a few "ship" people that's fine, but if that's only 1% of them are you really going to alienate the 99% for the extra 1% growth potentially losing up to 50% of your readership? There's fan comics for the 1% or write a separate short side story. Don't endanger your story if a love story has no place in the plot.