I don’t like this either. I think maybe people are more used to this in the US, but I personally think that if you can’t be objective you need to be more humble in your communication.

… of course Coke can trash-talk Pepsi and vice-versa… but if I’m making a technical assessment of competing products or software platforms I get a bad feeling of anyone using those sales tactics.

That can be true, especially for objective facts, but I would expect such criticism to be biased to the point of unreliability - "We taste better than x (according to our staff)", "we have higher quality than x (at double the price)", "we’re like x but cheaper (and we have nearly 20% of their features)". And even then, as an input there can be value, but it's helpful to at least know that it's coming from a competitor so I can anticipate the bias.