I agree with that tho. Expansion packs were usually good deals.
DLC was broken from the start because of Microsoft requiring every game on Xbox 360 to have DLC. So you got stuff like 2$ weapon DLC in games that had a substandard number of weapons (ME 2 and DE:HR, for example, had only 1 or 2 weapons of each type, and like a dozen total, in a AAA shooter game), or the Mirror's Edge devs literally tossing internal testing content in as time trials. And since in that era most AAA games were released on PS3+Xbox 360+PC at the same time, it was basically mandated that all AAA devs on all platforms needed to find an excuse for day 1 DLC.
I don't think developers or fans really wanted it. Developers considered DLC with a conventional (aka not FTP) distribution model kinda a waste of time, since you could never sell more of it than the base game, and since DLC was usually both cheap and unpopular it didn't take many man-hours for you to be losing money. Since fanbases tend to decline over time without free updates, DLC is most profitable day 1, and as a result devs were forced to paywall content that they would have included normally. And the fact that it was normalized because everyone was doing it, meant that producers were enabled and encouraged to be moneygrabbing and force devs to paywall things.
From a developer perspective, the most toxic aspect of DLC was that it would split multiplayer communities. Many games of that generation had tragically short MP lifespans, dead within 3 months at the absolute most. What happened in many cases is a map DLC would be released, and either the playerbase would be split into multiple queues (which would inevitably result in one queue or the other dying, and many people leaving the community), or worse, everyone would be put in the same server but people would be kicked if a DLC map they didn't have came up in the rotation. Halo 3 and CoD could survive this by sheer weight of players, but many new MP titles found that a map DLC would be the kiss of death, torpedoing a MP community within days.
Expansion packs like Brood Wars had similar problems, but the thing is since games weren't a service yet that was the only real way devs had of extending a game's lifespan. Game communities naturally die off if no new content is added. I do believe there are better ways to keep a community going now, but for a SP game I much prefer expansions to DLC (well, newstyle DLC, its all DLC in the end). For MP communities the most important thing is to never split the community, so neither expansions or DLC is the way to go there, unless you're very careful about how you do it.