Because DOGE is where I learned crypto. It got me into things on a hands-on level. Bitcoin is the grandfather, but it was intimidating, and not always entirely welcoming. Dogecoin enabled me to fool around without fear.
Because the Doge community is fantastic. In the early days, while trying to figure out things blockchain, the Dogers were very inviting and kind. They tipped me DOGE, which I could then use to mess around with and learn. It was like the Bitcoin testnet.
Because DOGE is fun. Cryptoers can be far too serious. Sometimes you need a break from talk about improvement protocols and forks and Satoshi's true vision and revolutions and fighting tyranny and saving planets and such. All things have their time and place, but, Wow.
So, include, DOGE, the non-serious "joke coin"? Yes, seriously, Dogecoin...and largely for that exact reason.