These principles are a very important part of a good game strategy. As with all poker advise, it should only be applied in certain situations. Take
pot odds for example. Say you are in the BB and UTG raises 5x the BB. Lets also say there are 3 callers before you. If you have 7-2 off suit then pot odds of nearly 4:1 looks great but will probably only result in losing more chips. Now say you have A 10 suited which has a higher chance of winning a 4 way pot. All A 10 suited has to do is win one out 4 times in this spot to break even.
So, as for EV, 7-2 would have a lower EV in this situation and proabably shouldn't be a call (unless maybe you want to add in implied odds) and the higher EV of the A-10 hand with those pot odds may make the call closer to profitable in the long run.