Honestly it seems like you might be the one basing opinion on a fantasy.

Not really. Rules and deadlines exist for a reason.

What horrible hellhole do you work in where one toe out of line means being fired?

I work in the advertising industry where, yes, one missed deadline could cost someone their job immediately.

Sure, mistakes have consequences, but let the severity of the consequence match the mistake. Costing my company hundreds of millions in fines will surely land me in the unemployment line, but misbooking a trade ticket gets a groan or a laugh from my manager and a little ribbing at best.

Who cares? This is anecdotal. Many bosses would fire someone for misbooking a ticket.

On the scale of severity, ops mistake is nowhere near "firing" level.

According to who? OP is in college which is not simply a place to earn a degree; it teaches you valuable life skills. OP didn't follow instructions properly (like everyone else did) and now wants a free pass and is being told what they want because of people's feelings.