I'm not sure to which meetups you are going, but Meetup.com is just a platform with a great reach. There'll always be corporate sponsored meetups in cities, but if there would be no Meetup.com they'd post it on Twitter or sponsor conferences in the city. I actually like it to check out other offices in the city from time to time and I don't mind the one talk from a person of that company, it's just fair as they provide the venue and food.
Especially if you are coming to a new city it's a great place to find out what's going on and find your group. It's nice to have a centralized place for that and makes it very easy to connect with people. (At least in my experience here in Berlin)
I use it in the distant past for language and photography socializing in a big capital city. I looked not long ago and most groups were now tech based that were clearly startup pitches and other "business" related things instead of cultural and social. Everything seems to get ruined by people trying to squeeze money out of it like the internet in general. I was just thinking today for some reason about when Omegle started and it was cool talking to normal people all over. Less than a year later it was overrun with scammers, spam for websites, and other nonsense. Skype is another example even further back. Everything that gets any attention ends up like this...twisted and ruined for profits. Has really ruined my faith in anything and anyone at this point because it all just gets gobbled up in pursuit of riches.
Especially if you are coming to a new city it's a great place to find out what's going on and find your group. It's nice to have a centralized place for that and makes it very easy to connect with people. (At least in my experience here in Berlin)