Generally speaking, all investments change value due to an imbalance (real or imagined) between supply and demand.
In this case:
There is no limit to how many Dogecoins can be produced;
The production time is very short;
More than 100 Billion are currency in circulation;
There is currently no real commercial application.
Its difficult for me to see any reason why the price would rise under such circumstances.
Well.. sometimes logic doesn't work in cryptocurrency market and as a result we have coins such as DOGE going up. All of your points are valid, and ideally this shitcoin should have died down a long time ago. But somehow it managed to build a large and loyal user community, and they have been successful in keeping the coin afloat. But we need to see for how long they can sustain this coin, without any sort of real-world application. At some point, it is going to collapse and when that happens the DOGE fanboys will be running for cover.