Which is more admirable. Those who reject/abandon and then suck up or those who sucked up from the beginning? Why?

Those who suck from the beginning. At least those are consistently sucking suckers.

Depends on the situation.  There are situations where one may do well to admit a lost cause.  Other situations there may be gain in pushing on.  The difficulty is determining which decision is best.

i dont think any of it is admirable