There is nothing wrong with spending real money on Gaia. For some people, this website is a hobby. Do you have hobbies? Of course you do. I'll bet you spend money on them too. It doesn't matter if these people choose to spend their money on "just pixels," as your hobbies are just as replaceable and easily discarded. Video games, for example. Sure, the consoles you buy are physical, tangible things, but they serve the same purpose as Gaia items; entertainment. But guess what, that system will soon become obsolete. You're gonna end up spending even more on yet another system and more games. Some people may not have the money to spend hundreds of dollars on the next big system, plus $50ish for every new game they want. In the long run, the people you call "pathetic" for "wasting" their money on Gaia will have spent less money for that same entertainment. And hey, rather than being replaced by the next big item, whatever they bought will most likely increase in its Gaia gold value.
It doesn't matter if you're not into video games, it was just an example. People spend a good deal of money on so many different interests of theirs. Music, movies, clothes, games, photography equipment and so on. The list could keep going and it's all more expensive than spending a few bucks on a website every month. Who are you to tell people that they can't, or shouldn't, spend their money on their interests, even if it's a website?