First of all, how do people even know it's YOUR ship? Maybe they do it because they want to. Not everyone has the same opinion.
So what, if some people like Hetero Spamano than yuri Spamano? I happen to be a yuri shipper myself, but this is just ridiculous. If you wanna ship your yuri, then it's fine. Because screw all the little shits that say it's gross, that's their problem. You can't stop billions upon billions of people who ship it heterosexually (or both).
Now, I'm not trying to come off as nasty or bitchy or anything (besides, I barely know you), but there are just some people who have different taste in things. If they don't like yuri, then they shouldn't even be looking at lesbian anime chicks anyway. It's not your fault they want to be hypocrites when they probably ship yaoi, claiming yuri is gross, they need to check themselves before trying to criticize.
And just because people make it hetero, doesn't make it canon; only Himaruya can decide that because he made their character. But, I'm pretty sure he hasn't thought about making any pairings yet, so I wouldn't worry too much about it if I were you.
But, I understand the whole yuri thing because all we see is mainly yaoi and not enough yuri to go around nowadays, which makes yuri so underrated, making yaoi overrated. Of course, I roll both ways but I'm more neutral. But some just want to be jerks and judge people for what they like.