How about Micro$oft allow modders in the community to distribute their mods to fellow MineCraft players for free if they want to? Some people are not obsessed with money, they make mods for fun and want to give something to the community. So why does Micro$oft not allow them to do this?
C'mon Micro$oft, show everyone that you're not rabid capitalists, and do something nice for the community for a change.
There are plenty of skins, add-on's, maps, and texture packs that are all available for free. Just do a google search and you will find thousands of them.
If you are playing on iOS, Android, or Windows 10 you can install all of these to your heart's content. Microsoft/Mojang even makes it pretty easy for you to do so, just download the file and double click on the mcworld or mcpack file and it will automatically install for you. Almost all skins that you will find online will work just as easily. Just download the skin and then in Minecraft navigate to the folder where you saved the skin file and select it.
The only people that are currently constrained to using only the marketplace in the game are the console users. Simply because there is currently no way of installing external content into the console version of the game.
Mods are a completely different story. The only version that can currently be modded is the Android version, but that's a discussion in and of itself as none of that content is even sold in the marketplace to begin with.
I am not a big fan of the marketplace myself. I have bought a few things there (some cool maps), but the majority of it is just a bunch of fluff that I'm not interested in. Yeah, there are the maps with dinosaurs and safari animals, but you could probably find a similar add-on that does the same thing for free if you do a little looking around.
Microsoft is not forcing anyone to use the marketplace, nor are they forcing developers to put their items there either. Again, the only people that currently have no other option are the console users. However, this might not be the case in the future as Microsoft/Mojang have promised that they are working on a way to at least use custom skins on the console. Hopefully this will include add-on's and world imports as well. We'll have to wait and see what happens.
Does Microsoft want you to use the store? Of course they do! They are a business just like any other. The point of a business is to make money for its investors. You don't make money by giving away everything away for free. It's up to you as the consumer to decide whether you want to purchase the content or not, nobody is forcing you to do so.