Automatron adds a lot more to the game than Anchorage (Fallout 3's first DLC, which was also 10$ at launch). Anchorage was a compelling story, kinda. Maybe. Depends on how you look at it, since the story was just a simulator and wasn't even real, so ye'h. It was an interesting and fun experience, but it didn't do much... It's more of an easy 1-3 hour long story and you get a bunch of items at the end. Most of these items people don't really use and they just ended up being added on. Automatron adds in it's own 1-3 hour long story but also the robot customization, new actual areas, new factions to find randomly in the wasteland, and so on...
I rather have Automatron, which gives me the 1-3hour long story but also gives me a crap ton of extra playtime and enjoyment via everything it has added to the base game than an Anchorage DLC which was just a small story and nothing else... Which was most of Fallout 3's smaller DLCs. They were just one area, one small story, etc and were completed easily but added almost nothing to the base game except for the rewards for doing them... I rather have Automatron over those DLCs. This is even including The Pitt!
Automatron is literally on the same level of those DLCs... Just adds a lot more to the actual base-game rather than just one area, some items, and one short questline. Plus, honestly, the questline of Automatron was very enjoyable like the Pitt's and much more enjoyable for sure than Anchorage (Anchorage was fun at first but got boring quickly. Mothership Zeta was just flat-out annoying to do in general and I strongly disliked that DLC).
So, you want more stuff added to the game? That's EXACTLY what Automatron does better than Fallout 3's and New Vegas's minor DLCs... Automatron adds a lot more to the base game than those DLCs has ever done because all of those DLCs were treated as separated beings. You do their questline, get some rewards, and was done with it. The only time you may go back to those areas was for specific reasons (Pitt's ammo press for example) or you couldn't even return at all...