I would quibble over the usage of "perfectly fine", but I get what you mean.

Most instant coffee is going to give a consistent, reliable flavor, and won't change that based on who makes it, how it's made, or any other factors that go into differences between individual pots of coffee. That's a useful trait.

It also has fairly consistent caffeine content since the batches it's made in are gargantuan compared to pots of coffee.

What it lacks is the diversity of flavor that choosing a brand, blend, or regional offers. It also lacks the depth of flavor, and the (opinion here) quality of flavor of even drip coffee. It can't have the same depth of flavor because the more delicate components just don't survive the drying process.

Now, that opinion about it tasting worse is just that, opinion. If a person favours a really strong, single note burst of "coffee" flavor without any of the subtle stuff, instant is awesome. There's a reason that espresso powder and instant coffee get used in baking instead of brewed coffee, and it isn't just convenience/water content. If you want that essence of coffee taste, the freeze drying process will bring it way better than any reduction you could do with brewed.

And you ain't lying about the convenience. Coffee you can carry in a pocket, make anywhere with nothing but water and a container. You can even do it without hot water, if you really need that hit of caffeine.

All of that being said, I have not, and likely never will, have instant coffee since I had to cut/minimize caffeine. Never have liked the taste, so without the ability to handle the drug aspect of coffee, there's no reason to suffer a taste I don't personally enjoy.

But anyone that does like it? Rock on my coffee brothers!