OP, it appears to me that your expectations of Solo mode don't match reality. You really need to consider exactly what "Solo" means in ED. As has already been mentioned the Modes (Open/PG/Solo) are nothing more than a sort feature that controls who you may encounter when you play, it's does not alter the wider galaxy, or the opportunities on offer. The Galaxy is a single environment, shared by all players at once, in real time.
You, in Solo, may be looking at a mission board at the same time as another player in Open is looking at the same listing. They will be entirely the same, the mission generation system in game doesn't care which mode a player is in. If you aren't aware, all missions are procedurally generated based on the given system's political/economic/justice state. These missions are generated without regards to mode.
On another note, limiting your own game play (i.e. not using engineering) should not affect what the Galaxy needs doing. Your self limiting has consequences such as; missions being generated that are outside of your capabilities. The game, in general, offers means to alleviate these barriers. Choosing not to engage, can't mean the game has to play at your level. You must rise to the challenge, or accept the results of your choices.