Maybe I'm missing something here but this seems like a really silly complaint.
Just off the top of my head
A complete rework of at least 3 sub classes
A complete rework of the weapon loadout
An entirely new story
Improved Graphics
4 entirely new locations
A slew of new strikes
A slew of new MP maps
A reworking of game currency
A reworking of multiplayer across the board
LFG systems and Guilds
Friendly AI characters during gameplay
Improvements to how activities can be launched
Entirely new loot
At least 3 new weapon archetypes
+more I'm very likely missing
Why does Destiny 2 look like DLC but Uncharted 2 or Borderlands 2 or Halo 2 or Mirrors Edge 2 or basically any other sequel doesn't "look like DLC"
Even in Destiny's big DLC Taken King we only got 1 new location and some mild system quality of life improvements. Destiny 1 was certainly a game that evolved but not too the degree that D2 is changing things.
Additionally why does it matter if it looks like "DLC" or more specifically an Expansion.
World of Warcraft gets similar priced "expansions" frequently and that's a game that require a monthly sub to play. People don't really complain then.
I'm basically just trying to understand the perspective of people who feel this is more like a DLC than a Sequel and what basis they are using for comparison
The basic answers my friends, who are deep into destiny, tell me are, "It isn't adding anything, it's just reworking everything."
There are still only 3 classes, even if they work differently. All the maps are different, but MMO's do this all the time, WOW's expansions shake things up in similar ways.
New Strikes, maps, zones, raids were things that would have continued even if Destiny 2 wasn't a thing and they kept Destiny as a games-as-service model.
It feels like this game is made for people who were starving for more destiny content instead of people who were looking for massive meaningful changes. It's more of what was there, but nothing feels that much bigger or newer.
It's fair to say it feels like an expansion, especially when you look at MMO expansions like FF14's or WoW's that have a similar or greater amount of content than Destiny 2 seems to have. That's not a slight against Destiny 2, it's doing what would be considered to be on par with other MMO's. The PVP being reduced in scale is a real interesting direction to go in IMO. For your numbers to go down rather than up is...uncommon at best.
And honestly that no dedicated servers thing is real crappy.