TinyRustyPanda I think you asking the wrong question: why wouldn't you put a romance in a story? Are your hero some Hermit, or someone put a knife to his throat threatening to kill him if he got feelings for anyone? Lust or love are natural feelings, and suppressing them without reason makes readers doubt the whole plot as forced and unnatural.
It's like "MC doesn't have any brief feeling for the most beautiful girl he ever saw, while knowing she is in love in him" and "MC doesn't have any need to breathe, while everyone around him does - and it's normal just because I (author) said so" are on the same level of reasoning.
A lot of readers can accept novel with zero romance in, they just need a reasonable explanation of why is it not there.
For example, a novel about MC forcefully transferred to another world, he escaped slavery after summoning, and while running away freed two female slaves, and they become his companions. Later author wrote a dialog between MC and a male friend about those two, asking why MC doesn't accept their feelings or make a move. MC said that he still wants to return to his world, and having a romantic relationship with any of those two will be a huge moral factor that might keep him from returning, that's why he visits brothels regularly, but keep ignoring his companions. And that's a reasonable explanation that toned down cries about romance.