Earlier quoted context omitted.
im not sure the "amateur" needs changing, it could be used to point more users to middle tier, we have something like that, where we call our first tier something that like that, and the second "smart" and people take the second one. also there is a decoy effect. we push our middle tier like that without "fake" most popular tier badge. we don't have a free tier.
Amateur, at least in common American English, is virtually never used in a positive or neutral sense. It should definitely be changed in anything marketing-related.
"Amateur astronomy"[1] doesn't have negative connotations. And I don't think this is an exception that proves the rule - as a native speaker of North American English, amateur can have negative connotations, but that isn't the default.
That said, in this particular case, something like "hobbyist" might fit better.