I think what pisses me off is the bloody research. in a previous battle i had teched up and should be more then ready, but no they send me into the lions den back in the stone ages. if the AI was smart it would just rush me and it would have been over.
Some games do get around it by giving you a base and some techs, others are just unforgiving and not giving you the resources for a risky undertaking. i remember in AOE2 some of the earlier campaigns where you advanced at most to the castle age so no trebuchets to siege bases, its the good old bashing at the front door with battering rams until they give way.
Warzone 2100 was nice in that your first base was kept in the campaign until you moved to the next campaign area. Your units gathered exp and could be taken to different campaigns as well. but there was a point that you still have to build a small base as you flew to different warzones to face the enemy. You could keep ferrying 10 units each time, but its not practical and its better to sustain your units as long as possible in the combat zone.