Why is that bad? They look at a nice, easy to read but disproportionate chart, come up with an idea that helps advance their cause, and work it into their presentation. That is how it's done, and it does not require mathematical rigor or loose ethics.
This is apparently a very offensive line of reason here, judging by the downvotes I've acquired for pointing this out. I find that to be interesting in its own right.
I try to assume ignorance over malice which is why I characterized our hypothetical middle-managers as clueless rather than intentionally using misleading data in my prior comment.
If the case is that they know the data is incorrect/misleading but they use it anyway to advance a cause that sounds like the kind of internal politicking that cripples many larger businesses' ability to make good decisions. So IMO that's worse than just being clueless and I no don't think it's very ethical.
Now maybe you're saying that it's possible to get the right idea from a misleading chart and get some value from it. That's true, but it's also true that you can get the wrong idea from it and make a poor decision.
It's bad even for those customers who want a result, because they will be hoping that the reputation of the firm reprinting the data will cause others to neglect looking into the figures.
Look what happened here: if either RIM or Microsoft were relying on the data to be under-analysed (not saying they were - just an example!) then it would have blown up in their face fairly spectacularly. And Neilsen is a reputable firm!
Try looking up the Mindcraft Windows NT vs. Linux benchmarks also.
This is apparently a very offensive line of reason here, judging by the downvotes I've acquired for pointing this out. I find that to be interesting in its own right.