That's one of the schisms in the casual RTS audience (the hardcore audience always operates on both levels at full speed), emphasis on using units well vs emphasis on building a big base and economy.
RTSes are by nature unforgiving. The economy is exponential to a certain degree, you spend money to make money and the faster you do it the faster you build up more money and a bigger army. In an FPS you die and you respawn, in an RTS you lose an army and you're out those resources. Some ditch the entire resource system and make it about having a refilling pool of money to invest into units (e.g. World in Conflict) so there's no snowballing but that of course removes the ability to build more units or a satisfying base.
Battleforge (EA) have built the best resource system to prevent snowballing.
You had two type buildings: resource and tier. You generate resources from those buildings into the main resource (Power) pool for units/spells/abilities/combat structures. However, used (or dead) things return 80% of their value to the "void". The void is unavailable directly, but depending on how much of power is in your void, it trickles down back to the main resource pool.
The result is that when the players lose their units, they have a boost in the economy. It was a system which didn't place towers to fall back or penalized the winning player directly.
As far as base-building goes, the discussion is deep and it is important to understand what people want from base-building mechanics. You will not find a unified opinion or a compromise, these are different mechanics.
Do they want a pure economy simulator where the army is just quantities of rock/paper/scissors units?
Do they want something like Stronghold Crusader where designing and building the actual layout of the town successfully is the most important part of the game?
Do they want the game which is about combat but has some base building elements like Warcraft 3 or Dawn of War1?
Do they want a game which is about tactics and combat like Company of Heroes 2?
In all of those examples, you get the choices between expanding resources or army, and whether you want more army now or tier the tech to get better units. This part of RTS games isn't impacted by whether you build a physical base or not.
You (in theory) can have both: deep tactics with complex units and deep economy town building. However, both of those mechanics individually are more complicated than genres of popular online games, so asking the player to master both of those elements in real time is too much even for the existing RTS players.
I totally disagree with that. Base building is one of the great things about it and is a key part of the strategy. You can leave it and still have it accessible to new players. There's room for both types.
Please explain how it is a key part of the strategy.
Total War games are difficult in army compositions, tactics, formations and the real time management of everything (if you are playing online). The inclusion of magic and aerial units in Total War expands the tactics and complexity further.
