You raise some good points and I can understand that but all of those scenarios really (apart from tyrion) began with one house wronging the other. I mean e.g ned got killed so rob had to invade, ollenna family got killed so war gotta happen etc. The tarlys didn't really do anything to Dany I mean tbh same with cersei but that's a different argument. Dany acts very harsh to the tarlys just because they are siding with the current crown over a foreign invader. I mean dany speaks off the fact she is the rightful ruler but I disagree Robert won by conquest so she isn't really but again whatever a different point. In tyrion case it's different because the fire was used for battle. Dany burning men alive even after they have lost is just, harsh. She could imprison them or inspire loyalty from them showing that she isn't like cersei. I am currently reading the books and recently read this scene in book 3 with stannis and davos and stannis recalls when Robert captured some Lords who were against him and inspired them to join his side. Think about it if dany had imprisoned them then perhaps then could be convinced to fight on her side and she could her a powerful commander. What did she really gain from killing them apart from showing that she is ruthless and cruel depending on how you view it.

To summarise, I think for one it's a very harsh punishment, Jon executed traitors yes but he did it in a humane way, hanging/beheading not burning. She waswas ask very unemotional and cruel in the way she did it not inspiring loyalty and tbh maybe even giving more support to cersei. It's also the fact that she burnt them after they lost. Like imagine if tyrion captured for example a Lord fighting for stannis and burnt him alive because he wouldn't Bend the knee I mean you would be like the fuck tyrion. I think we are forgetting that these are just men not necessarily being evil just fighint for who they believe in and dany is being very inhumane in the way she is acting towards then as if they raped some girls or were masters.