I think we have to realize that arranger keyboards by and large ARE toys, which is why they are sold in the toy departments of many stores. I have seen arranger-type keyboards made for toddlers. Some PSR models are pretty childish, you gotta admit. Then again, some people would buy a PSR 9000 for the same reason they would buy a toy: for them or their kids (or grandkids) to play around with.

This is actually our secret connection to our audiences: while most regular people have never touched a Fender Stratocaster nor would they know what to do with one, many people have played with an arranger keyboard at some point even if it was just in a department store or at a friend's house. Parents buy them for their kids hoping to spark some musical interest. Professional performers that can really perform very well on one have an immediate connection with average people.

Arranger keyboards will never impress snobby keyboard salesman who's commission comes from big-ticket keyboards, or wanna-be rock stars that buy keyboards based on what their hero superstars play, but for regular people that will comprise the majority of your audience, arranger keyboards are familiar and cool.