I would actually like to discuss this, if that's okay.
What I meant by the amount of thought is that, there really is much more to making pony crossover characters than simply grabbing symbols and putting them on the pony's flank. The color scheme can take some time to develop. The position of the pony can help the character to be even more personified. Now, I will admit this particular picture didn't take as much time as others (partly because back then I didn't have a tablet, or much pony-drawing experience!). But, take a look at this crossover I did just a little over a month ago: here. I'm not sure if you're familiar with BBC's Sherlock, but that was the character I was attempting to make as a pony. To make a pony crossover, you have to first consider what type of pony (unicorn, pegasus, earth, etc.), and fit that into their personality. I made Sherlock a unicorn because we not only needed him to be a unicorn for the crossover roleplay we were doing at the time, but also because I thought it might help enhance his personality. Then, you have to consider the style. Unlike the Slendermane vector-style pony, I used a realistic style on this because I thought Sherlock deserved the effort. And then, color schemes. Some pony artists use the human skin tones for the main color, but I try to fit them into the MLP world a bit more by picking a different color. I chose a dark purple-ish gray because I wanted to bring out Sherlock's slightly darker side a bit more. And then, of course, you have to figure out the mane, while is divided into three sections: forelocks, mane, and tail. As humans don't exactly have these three things, it can be a little different changing a human hair style to a forelock hairstyle. And the tail should be similar to the mane style as well.
And of course, there is more, such as position and shading to help a character's personality shine through. For me, pony crossovers not only allow me to enjoy the MLP fandom, but also allow me to combine it with other fandoms as well. They are a way to test one's skills in combining pony anatomy with that of something entirely different. My crossovers are not meant to annoy people by any means--they are meant as admiration for not only one but two fandoms.
I can understand that there are some people who make pony crossovers that are annoying. Either if they aren't well-drawn, or are biased towards one fandom in particular, or if they simply show up way too much in the search results. But there are some artists who really care about what they do. I put a lot of effort into my art, and whether people like it or not I don't really care, the important thing is just that I can show my admiration for my favourite characters and fandoms.
Hope that maybe helps to explain why I feel strongly about letting pony crossover art pieces have at least a little appreciation? It really means a lot to me as an artist, because I have indeed spent many long hours drawing these. My time is quite valuable, so I only spend it on things that matter to me.
Thank you for giving me a chance to explain myself~