One reason could be that it's a Meme Coin. But it became pretty serious business back in 2014.
Imho Dogecoin is not taken seriously is because it's an inflationary coin. The supply is not limited and each block still brings 10k new DOGE into circulation.

Dogecoin is wonderful for learning, but its value means less and less every day. And in this business, if there's no money involved, it's not serious.

The obvious reason would be because bitcoin it is the first digital currency ever made.  All existing and emerging cryptos are based on bitcoin   Its prices are likewise based on bitcoin.  So obviously since bitcoin is well known compared to dogecoin, investors will choose bitcoin.

Not me. Bitcoin is the idea, alt-coins are variations of the idea. Mostly they are scams to fix bitcoin's big problem. The problem being that the developer does not have your money. So if you can't compete with fair money (bitcoin), then change the rules and make an alt that favors you.

Of course because bitcoin is more popular than dogecoin, or even more popular than other coins out there.
Many people know about crypto currency first because they discovered bitcoin, knowing news about bitcoin, and heard news about how great bitcoin is.
Rather than news and impact about dogecoin, it's not comparable to bitcoin.
That's why bitcoin surely is better, and taken more seriously by people out there than bitcoin.

Bitcoin is more popular than Dogecoin or any others coins exist. It was more invested by many people and the best of all, it has the highest value in the market compare to other coins. That is why many people take seriously on bitcoin than any other coins. Dogecoin is not taken seriously is because it's an inflationary coin. The supply is not limited and each block still brings 10k new DOGE into circulation.  Dogecoin is wonderful for learning, but its value means less and less every day. And in this business, if there's no money involved, it's not serious. A coin based on joke is no competition for bitcoin. Look into the history of Doge and you will see that it was a joke coin from a popular meme.

Knowing that bitcoin is known than dodgecoin is not really a big deal. It is just a matter of choice where you choose to invest and of course referring to its valur. To be honest, I don't even know what dodgecoin is. Bitcoin is known through out the years and I guess accounted for being the pioneer cryptocurrency.

Dogecoin is coin created for fun.

Are you asking seriously? How such strange question can came to your head?
Bitcoin is a father of crypto and Dogecoin is just an joke currency. Dogecoin don'thave active developers and it's just copycat coin without big perspectives.
Only 21 million Bitcoin will be mined, while Dogecoin have unlimited supply. It tells enough about both Bitcoin and Dogecoin.
You're not right. It's enough to look at price charts. Despite factors that you mentioned, Dogecoin price are going up slowly. Just look how much Doge price increased within a year.

maybe dogecoin because it has a very large supplay total, and the price is very cheap. while the bitcoin supplaynya very limited only 21 million. probably because many people say dogecoin is not serious, but dogecoin is good enough to be a long-term investment option