Re: MySQL versus PostgreSQL comparison
Well... yes and no. The thing is, both MySQL and Postgres are free and open source. That creates overlap in their market spaces. In terms of using them, yes, Postgres is more reminiscent of Oracle than MySQL. But when you're setting up a service or starting a project, if you're looking at MySQL you can also look at Postgres.
In early days, Postgres was certainly the more robust and sophisticated database. By far, in fact. However, MySQL with MyISAM ran a lot faster. Which made it the DB of choice for the explosion of web forums and CMSs we got in the late '90s and early 2000's that wanted lots of cheap, fast read capability and really didn't care too much about strict data integrity or sophisticated features. Also MySQL had (and has) less of a learning curve. Neither is especially difficult, but MySQL will make smart guesses about what you mean with lots of forgiving defaults and multiple ways of doing things. You can slap on an autoincrement qualifier to a field and you don't have to understand sequences (no, serial is not quite the same); MySQL will default to making everything case-insensitive (just to be helpful) which can actually trip you up but is a great example of how MySQL takes an approach of "I know what the users will want...". Another great thing is to compare query plans between the two. MySQL will give you a basic summation that lets you look at the output and go: "hey, it's not using an index on that join, let's add one". Postgres will give you all the nuts and bolts and let you go: "hey, I wonder if this would run faster if I to set the from_collapse_limit differently here".
Now skip forward and MySQL has more sophistication than it used to (assuming you're using InnoDB and not MyISAM nowadays). Postgres in turn has improved dramatically in performance. For many cases you can use either. But MySQL still carries that legacy of its initial popularity and still has an easier learning curve.
But an easy learning curve can be a two-edged sword. Taking just that little bit longer to really understand Postgres reaps great benefits, imo. It is now performance-equivalent to MySQL InnoDB at the least and remains the more sophisticated of the two. By choice, I will work with Postgres, though often enough I'm called in to consult on MySQL systems and I'm fine with that.
But TL;DR: I think it's absolutely right to talk about comparisons between MySQL and Postgres. They service a lot of the same potential market.
I think Word vs. Notepad is over-doing the comparison. Not least because Notepad is fine for its purpose and people might take this to mean that Postgres is bloated with unnecessary features. It's not, it's a lean piece of machinery, very elegant, very solid. I would go more with something like Surface Pro vs. iPad Pro. And I'm really not attempting to kick off a fan-war with that analogy. I just think that people will know what I mean. Both great bits of hardware, overlapping somewhat in target market, both with plenty of great features. Just one is that little bit more coherent, capable and planned. The iPad Pro is maybe a little bit easier to pick and go "this is familiar" and start poking things, but after a day or two that advantage is gone but one still has a better kickstand and some extra capabilities. But either might be fine for your needs depending on what those are. "Notepad" is a little unfair, imo. MySQL is fine and very capable. It's just that I think Postgres is the more sophisticated and solid. It's what I would choose to build an important system with.