Absolutely agree. I use the term "needy" with the understanding that I try to apply to all use of language. There are many connotations to all of the words we use to talk about emotive topics and it's quite likely that someone will have a problem with
any word (nice nor needy seem satisfactory). And not only at the connotations plentiful, but the denotations are also abundant. I'm pretty sure that if there were more suitable words, we'd already be using them. The search for the best word will continue, but in the mean time a common word with an agreed upon definition seems fine.
In this case I see a "needy guy" as someone who is ruled by his needs. Someone whose behaviour is dictated by those needs in unreasonable and counterproductive ways. We all have needs, yes, but we don't all start harassing the person who might satisfy those needs if it seems they won't.
Frankly I think "immature" is more accurate, but I suspect everyone would complain about that one, even though we're all immature in some ways.
But you're right, we shouldn't treat those guys as monsters. Hell, I was one of those guys! (a "needy/immature guy", not someone who'd go on Dateline...) What I would have benefited from greatly was someone telling me that that's what they saw in me. No one did so I had to piece it together over time, from hints here and there, distracted and confused by those times when a relationship was successful for a while, despite still behaving in that same "needy" fashion. Sure I might have denied it at the start, but if someone had planted that seed of doubt, I'm sure I would have saved many years of addressing that particular issue (and been able to move onto all the others
)