Hi nate. As with every tool, WordPress has to find a balance between ease-of-use and feature-richness. That means: The more features a tool has, the more complex it will become to use.
Concerning your problem, the WordPress developers went a very typical way: They implemented only some necessary standard features and let the user decide what they need for their special purposes – that means, you can download hundreds of plugins, which enhance wordpress in any thinkable way.
To give you a clearer anwer, I suggest a plugin like Sticky Image (well, developed it myself, so of course I promote it). It lets you upload images directly when posting, while automatically thumbnailing and resizing it the way YOU want. You can get to the plugin page here:
https://www.wp-plugins.net/index.php?filter=sticky+image&filter_search=Go…
