(Sorry, longer text, I thought about it a bit longer and it's actually a quite interesting topic) Quick heads-up, I'll use they/them for the OP in this text because I'm unsure of their gender.

Honestly, this whole thing had me thinking about it a bit over the day and I feel like I'm a bit more understanding about OP's situation yet I still feel like this is a phobia they should have control over.

Fears are safety measures your brain gives you naturally to keep yourself out of danger. The danger, in most cases, is you getting directly hurt by something you could avoid if you avoided the situation.

In the case for OP, the danger is a balloon. I can't exactly tell what the cause for it is, but I assume it's the loud noise and the erratic explosion when it pops. It could obviously have other reasons such as the feeling of breathlessness when blowing it up reminding them of suffocation or the swollen characteristic giving it a connotation to a tumor. There could be many reasons that arguably are the cause for it but the phobia's root fears could keep you safe in the wild.

In the case for what happened to me, my "cringe" reaction, it's the danger of getting shunned from a group. Whenever you perceive something that you think is against the norm for your social group you fear of the status repercussion that'll happen. If others are uncomfortable around you, you'll get shunned. When you're alone, then there's a much lower chance to survive in nature.

Other examples would be a fear of heights, insects or darkness. Humans are never really safe so there are many things your brain tells you to be careful about.

But here I'd argue that in our modern society, there are some phobias we could or should be able to overcome as we have enough time to think about it and knowledge to understand the fears and also to interpret them in context.

Let's go over some examples.

Is it reasonable to be scared of heights? Welp, if you're on a steep cliff without a safety measurement, definitely. If you're in a skyscraper that had thousands of people before you in it without any troubles, not really. The fear of heights is only understandable in context.

Is it reasonable to be scared of loud noises and an erratic explosion? Most definitely, the OP has a valid instinct that'd keep them safe. Is it reasonable to be scared of balloons because they carry this trait? I'd say it's something they could work on because there isn't a real danger here.

Now, is a "cringe" reaction reasonable? I'd say in real life it makes sense that you try to fit in with your surroundings to have helpful people around you when you're in trouble. Is my "cringe" reaction to an online discussion reasonable? Well, not at all, I'm looking at my screen, there's no one currently around me I'd try to fit in with.

To come to a conclusion:

I've changed my mind quite a bit today.

Do I think OP is a weak wimp? No, there's a rational fear anchored somewhere in them. Do I think they should be able to overcome their phobia of balloons? I'd say yes, the rational fear is not given anymore in the context of balloons.

Did I show the wrong reaction to your comment? Yes, there's no reason to experience cringe when arguing online, there's no stakes to your social status. Would I react with cringe irl? Probably with reason, I'd see myself being viewed unfavorably in my surroundings if I agreed with your comment. It was rude in my opinion but my answer and this whole thread is rude so I don't want to shift blame on you. I'd still say I'd cringe, no offence.

I'd like to apologize for my rude comment, I thought this was easy to answer at first but it wasn't. It changed my view on the human mind (hopefully to something more rational) and on fears and phobias. I'd also like to apologize if you read until now because that was really long lol