One meta belief I have, is that I think "on the face pursuing idealistic objective A, but actually being tilted toward selfish objective B" is better than "openly pursuing objective B".

Many seem to believe the opposite, typically saying something like "at least the latter is honest".

I feel like what this misses, is that maintaining the face of pursuing idealistic objective A, and using A to coordinate a large coalition, is a pretty big speed bump against attempts to pursue B too brazenly. When "the mask comes off", things actually become much worse, and strategies that pursue B at high costs to other values (including A, and also often general human decency) become unlocked.

Are there any good arguments against this intuition I have? (Whether generalized, or about specific situations)

why this is particularly bad: 1) it leads to intellectual dishonesty, and can only have a slippery slope from there; 2) it leads to race to the bottom: ppl are encouraged to do virtue signaling as much as possible while actually pursuing selfish goals as much as possible as the arbitrage space in virtual signal --> selfish goals are huge. And it left ppl who do not do virtue signaling as much in a disadvantages place, basically, create an incentive for ppl to virtue signal as much as not doing anything real as much. 

AND I believe we've already seen how this hurt ETH community.