That depends on context. A often comes with an implied, "underwhelming for everybody and thus it won't sell well."

No, it doesn't. You are inserting that implication so that you can poison-the-well on like-opinions later.

Please. While I'm sure people just talk about their own opinions in many cases, it also happens all the time that people criticize the specs or other attributes of a new product precisely because they think it won't appeal to the masses.