As a reminder, the context here is that you posted nodes like this one in Seekers of Perl Wisdom. The target audience is people who are new to Perl, learning Perl, etc. We have to assume that anything posted there there can and will be taken by newcomers as real advice (unless explicitly stated otherwise), which is why I, among others, will judge nodes there based on that.

The reason why I like to "reinvent the wheels" is because while doing so, I learn how stuff works.

This is absolutely a great way to learn and I fully encourage this! I would additionally suggest looking into the best practices everyone is recommending and trying to understand why they're being recommended, because you might find some of them useful, even as a hobby programmer. But as I've said several times now, iff you're writing this code just for yourself, your style is fine because TIMTOWTDI. (But you posted your code in SoPW, so the code is not just for yourself.)

Secondly, when I use someone else's code, I have to deal with potential bugs that they left in their code.

This is exactly what you are inflicting on others by posting buggy code!

The difference between a hobby programmer and the hired professional programmer ...

Being both a hobby programmer and a professsional programmer and engineer at the same time, I disagree with most of the generalizations in this paragraph, for example the quickest easiest solution is not always the best solution, at least if you take pride in your work (despite plenty of companies out there discouraging this, of course). But I do understand your explanation of being a hobby programmer, and I do take this into consideration as I write all of this.

I feel it's unfair to judge me based on past code that I wrote earlier.

I agree, and I've posted my really old code. But the node I was talking about is from last week.

Btw some of the things you have linked to that I mentioned earlier turned out to be really bad solutions, and I have since quit using them.

You might want to consider updating your past nodes with that information.

The two-argument open is still something I haven't gotten over yet. I think, I asked someone on here earlier to point me out the security flaw in the program, and all I heard was crickets. Nobody said a word.

The very first link in my post above contains an explanation of a potential security flaw... see also "open" Best Practices.

Like I said, I suggest you post your code in Meditations or Cool Uses for Perl instead. It's perfectly fine to start a post with something like "I saw the post PERL csv files to Excel and it inspired me to write the following code..." - I suspect this will be much more appreciated.