i would also put in that i think the planetary bonus's are too weak on larger maps. and would suggest reducing the frequency of ideology bonus's to 1 in 20 planets but buff them up quite a bit something like 500-1500% bonus rather than 5-15

i mean the 5-15% is nice and then i go well that's only equal to a single +3 adjacency and which is really not all that much.

I think there are two main issues here: one is that ideology needs to scale with map size, and the other is that we need more non-colonizing sources of ideology. The notion that ideology is too cheap is laughable on anything below huge map, which seems to me to be the sweet spot currently. With colonizing being the main driving force behind ideology, it is impossible to explore the system on the smaller maps. The idea of invasion events has been talked about, but that would mean that you would have to choose a military strategy to advance any ideology tree. There are some ideology events, but these are too few and far between to make much of an impact and you can't count on them.

I think there should be triggered ideology events that happen with certain milestones; the ones that give cinematics would be a good start. So first new planet, first starbase, first anomaly, first  capital ship would be good times to get an ideological choice. In addition, certain techs could give you a choice and maybe even at certain turns or population levels, some anomalies could give you ideology choices. Mutually exclusive 1/civ and/or 1/planet buildings that are granted through tech rather than the ideology tree itself would also be welcome. It's probably a little too much for the base game, but I'd love to see some quests put in to gain ideology as well. I think this would allow for advancement in ideology on smaller maps, while a scaling cost would prevent you from maxing out all the ideologies in the larger ones.

A follow up.  

For people complaining that ideology is too easy to get on larger maps, just set your planets to Rare. 

Started up a new game and decided to give the Yor a whirl.  Somehow I set everything to random and... well... I'm on turn 101 and I'm about to colonize my ninth and tenth planets.  On an Immense map.  It's a scattered galaxy, but shouldn't matter that much when it comes to the total number of stars.

It's not like I'm shirking things, as I am #1 in UP votes and am close to the top in # of planets held.  Near as I can tell, the Terrans have the most planets in the game.

They have 10.  Again, on an Immense Map.

And it's not like I haven't explored.  So far I've found around 120 to 140 star systems (it's a bit of a PITA to accurately count without sector lines).  And in those 120 to 140 star systems, there's been 14 total planets that are colonizable, including extremes.

...

Gonna need the ideology buildings in this game I think! 

I decided to try an immense map for the first time without thinking about changing my usual settings for small maps, and now I find myself at turn 178 with 58 planets, the entire Malevolent Ideology tree, and a third of the way through Pragmatic, and I haven't even met any of the AI civilizations (all of them are out there somewhere).  So I agree, Ideology needs to be scaled somehow.