Well, that just means they didn't steal the idea from Dragon Quest, that's all. But Dragon Quest didn't steal it either.
However, it was implemented similar to how Dragon Quest was, including the Egg Moves.
And no, putting in random lesser Pokemon instead of one Digimon is silly. Altaria is not honestly a better choice than Agumon, a major character.
They're one slot. Pokemon will have other slots, but it's not a relevant reason to avoid putting a Digimon in. The point is "Digimon vs Pokemon" here. The biggest reason they want them in.
There's also the factor of "What video game series does Bandai even have?" beyond Digimon, so... it's a far better choice than just adding yet another non-important Pokemon.
Altaria isn't even on Pichu level of importance. -_-
It has to be said, I don't, well, anything about Bandai, but a quick check on wikipedia and apparently they made chibi-robo (source wikipedia), We can all agree chibi-robo has a better shot than ....mon, can't we. Altaria is very important, it's on the extremely short list of dragon/flying types that you can use in a regular team in pokemon!
Seriously though, 'Altaria isn't even on Pichu level of importance.' Yes, this is true, Pichu is pretty damn important. 5 reasons Pichu is important:
1) Various Pichu brother shorts.
2) Large role in Arceus and the jewel of life.
3) Had a whole event dedicated to it, which actually builds up Silver's back-ground.
4) Had a change on it's body while keeping the same on it's normal Pichu, spiky-eared Pichu. This is the only pokemon to do so.
5) Only the starring and most important role in the 2010-release Pokemon ranger: Guardian signs, the newest installment in the pokemon ranger series.
These are the reasons why I think Pichu actually has a pretty good shot at returning, I mean, without hurting itself and with a completely different set to Pikachu, possibly implementing the ukelele, and yes, Pichu is more important than Pichu.
Oh, and Pokemon and Digimon are battling series', even if they aren't entirely similair, they're close enough to be endlessly compared with each-other and obvious rivals. You can easily compare them in chances for smash.