There is always an option what taking it in the evening is magnitudes better than not taking it in the morning at all because you skipped it because you need a shower.
Always remember what you are just an another patient with your own quirks.
For the drug I take every day (Levothyroxine), research found that evening was worse, but the explanation was poor compliance - people forget to do it more often compared to the morning. Same reason the contraceptive pill is less effective than you'd expect in real populations, compliance is poor. If you're the sort of person who can actually take it on time, every day, without fail, it's extremely effective, if you aren't, not so much. The choice to include "dummy" pills is because of improved compliance - remembering to take it every single day on the same schedule is just easier, so adjust the medication not the instructions.
What annoys me here is that these things are hidden - if the patient knows that compliance is better (ie their chance of staying with the medicine and so of getting better) does it really reduce said compliance?
What's hidden? Compliance means you directly benefit from the intended functionality. Like anything else in life you can insist on more documentation but most people don't care.
Always remember what you are just an another patient with your own quirks.