It's not that they weren't appealing; they simply were not seen by kids. And I can guarantee you that not one person I know (outside of these forums) has ever even heard of Starblazers, let alone seen it.
You might not *think* the lack of toy support was an issue, but the reality was it was a huge issue. Robotech lacked toy (and thus commercial) support, and in many markets ended up with poor time slots (if shown at all). Again, this has been covered countless times over the past 20 years.
Whatever you think of Robotech, Macross, Southern Cross, or MOSPEADA, the fact is that they were not very popular in the U.S. It is my opinion that this is because they were not widely seen, not because any of those series sucked.
Robotech is not the Transformers. It's not GI Joe. It's not the Thundercats. Hell, it's not even as popular as the Smurfs. It has a niche market, nothing more, nothing less. To expect more out of it is unrealistic.