One thing bugged me... it was the Marth argument.
It was something that I admittedly couldn't counter really. The spear is what makes Bandana Dee unique, but it's still something like him having his strongest point be at the tip. I was then thinking of an extreme Marth, where damage and knockback are at the greatest at the tip and terribly weak everywhere else, but I didn't think that would be too appealing.
That's when I had an "AH HA!" moment. I found how Bandana Dee can represent a play style in another fighting game that is not represented in Smash.
May I present to you all Vega from Street Fighter 4:
If you notice something, after taking some damage, his claws come off! He will need to fight and pick them up; without those claws, his damage output is weaker.
I thought... what if Bandana Dee had this mechanic?
Bandana Dee without his spear would be much more crippled. His attacks would become pathetic and lack any sort of range. After taking enough damage, he would lose it. As a result, some of his specials are either inactive or severely weakened. While it might not make sense in context of the Kirby series, where he would throw his spear and gain a new one, it makes sense towards his character since he is a klutz. If someone else grabs his spear, they would use it as item and if Bandana Dee's spear is removed from play too long (as in, it was thrown off the stage), he would generate a new one.
This is different from Robin because Bandana Dee will always have his spear unless enough damage has been consecutively taken, unlike Robin who uses his Levin Sword and Tomes after a certain amount of times.
That is how we can counter the Marth argument...
By making a whole new play style unseen in Smash.
You don't have to agree with my idea and I understand if you don't like it. If you want, I can create a moveset for it.