It's actually a lot simpler than that: I can't afford it. I don't have the free cash at the moment. I am focused on eliminating debt and increasing savings and I can't do either if I spend some grand on an IDA Pro license.
I guess there aren't student loans for IDA, but there definitely is employment. Once you become competent with IDA, you can apply for jobs like these at my workplace: https://news.ycombinator.com/item?id=19284153 Being competent means you can navigate around in a binary without symbols, that you can mentally convert assembly to C, and generally that you can find things of interest in the binary and understand them.
Binary Ninja (binja) is $149 from Vector35. That might be optimal for you.
I realize someone's probably going to comment that I'm an idiot for living in the Bay Area, but consider this: after living expenses, I still make a fair bit more than I did in Detroit, and I much prefer living here. So it is what it is.
I think in a few years I should be more than capable of buying an IDA Pro license, but as it stands I am not taking on that debt for a hobby. As for whether or not I will get a job doing reverse engineering, I think it's unlikely any time soon, though certainly possible in the future.
That's a lot more context than I feel is necessary to explain why I can't casually drop $3k-5k on a hobby, but hopefully it makes more sense.