Um… Not since the beginning – he’s not really defined in New Mutants #98.
In fact, it would have been a lot better if Bob Harras and Marvel did not let happen what it happened but… oh, well.
But they gave him character afterwards, that is undeniable, otherwise no one would be looking for NM#98 or early X-Force…
True. Wasn't until the late 90's Deadpool was defined (and continued to evolve). Regardless, he was a head of his time, and it took hime a very long time to find broad acceptance. Some people still have difficulty accepting him as a real character.
What you say it’s very interesting, it also gives a hint on how Deadpool relates to the way Marvel changed, and made questionable choices about their poetics.
It would be interesting to use it as a starting point for a broader discussion about the character and Marvel itself.
I was referring to Bob Harras' (and Marvel's) decisions (and questionable behavior towards Louise Simonson and possibly Claremont) at the time: they trashed a good and innovative series like the New Mutants was, and Deadpool happened to appear there first, but it wasn’t obviously a defined character.
I see Deadpool in the lineage of characters like the original furry Beast, the Foolkiller, Howard the Duck, Omega the Unknown, the late She-Hulk, Power Pack and a few others: most were characters truly ahead of their time, and not always have been developed, or if developed, not properly.