There is a spectrum of meditation activities. What does and does not constitute 'meditation' depends on one's training. I've heard the arguments of "I don't need to meditate, running is my meditation", which some may agree with to a certain degree (like Dan Harris' 10% Happier book) and others strictly disagree with (like pretty much anyone who's done a week or two-week long retreat).

In the end, the question is, what are you looking for in meditation. If all you're looking for is to slow down a bit and maybe get some benefits along the way, Headspace is fine. If what you're looking for is to transform the way you're experiencing the world (which is very much possible through meditation), Headspace isn't gonna help you much. It might be a good stepping stone, though.

We all have 'flags' that turn us away from a particular source of meditation. For some, it's the music employed in yoga/meditation centers. For others, it's the marketing, as you say. For me, every time someone mentions the 'ancient texts' and its superiority, I cringe a bit. That, to me, is very much the antithesis to meditation--fixating on a single source of truth, possibly long forgotten, that is.