There is a pretty big gap between having heavy hands and having pillow hands. His punches hurt and stun his opponents he just isn't likely to get a flash KO unless they have a mediocre chin. Your "stats" are fraudulent also he didn't even really start being mainly a boxer until the Sherk fight and didn't start sitting down on his punches until the second Penn fight. Penn just doesn't get dropped his chin is legendary, he TKOed Gray with punches, and he dropped Bendo with punches.
Your opinion isn't supported by the actual facts I just laid out and isn't based on specific patterns you can site from his recent fights; it is just confirmation bias. Soft punches don't make your opponents head whip back and their legs stop and Frankie repeatedly achieves that.
A punch is a punch. Any punch thrown is going to have some negative effect on the person receiving it. Frankie doesn't frequently stun or drop his opponents. His hands may not be soft as I described them earlier, but they certainly don't pack much oomph either.
The post I was responding to also said that Frankie hits very hard, which, he does not. Also Frankie didn't drop Bendo, it was a slip. Carefully watch that moment back again.
He started boxing in his war with Tyson Griffin. He's been pretty much the same stylistic fighter he was all the way back then, but of course, he's become much more proficient in his style over the years. Since his UFC debut against Tyson he has liked to box and mix things up with his take downs.
When he starts dropping fighters on a more frequent basis, then I'll start to worry about his punching power, but as of right now, it isn't really a great danger to Bendo or many other fighters.
I'll take Bendos heavy variety of kicks and his ruthless ground and pound and crafty sub game over Frankies in and out 1-2 boxing combinations and quick take downs.
Edit: I believe it was in the Bendo fight when Frankies corner in between rounds were instructing Frankie to get in there and "score points" by moving in and out.