I'm getting ready to return to formal training. Training is Aikido is often difficult. This is not because of the hard work, that's something to expect and embrace, but it's because so many of the schools teach a flowery, non-effective form of Aikido.
A small rant: O'Sensei created his art as a martial art. The majority of his art is born of Daito-Ryu Aikijitsu, which was born of very effective Samurai battlefield arts. If you read what many of later students learned is that while he continued to do Daito-Ryu, he taught Aikido. A former Sensei of mine had this story passed on from his Sensei. The reason for this is that after war time in Japan, the Japanese were not too keen on people teaching martial combat.
Things had to appear to be more flowing. So when the local military poked their head inside the school to see what training was going on.... well, they were dancing. Smooth as silk.
But the truth of what was going on was lost on many students. Those that got it stand out and teach excellent waza. Those that don't get it, miss the effectiveness built into the martial art.
So, in a nutshell... much Aikido is poor because the instructors teach it that way.
As has been said many times, "Aikido works. Maybe YOUR Aikido doesn't".