I believe RT is financed in large part by and through the Russian government. Also there is no free speech in Russia and dissenters are often jailed and killed under suspicious circumstances, so ignoring the financing issue journalists are likely afraid to criticize the Russian government.
No free speech in Russia?
Just look at what people write here in Russian-language section.
The same zoological russophobia (spread by Russians who often don't speak any other language!) you can find in any social media, and nobody bans them, like in some other countries.
There are more than enough dissenting voices which RT is positioned to offset internationally.
And the main motiff of the dissent boils down to: Mr Putin owes us money - on the scale Mr Qaddafi used to pay everyone in Lybia, until Mr Qaddafi was killed by the beneficiaries, who used those money to buy up armaments.
Why don't we get oil revenues like in Saudi Arabia? Why do we have to work? and so on.
In Russia you can talk complete and utter bullshit in public, without any Political Correctness, or even basic decency limiting you - and a lot of people do talk. Admittedly some miniscule percent get jailed for that (unfortunately usually not the worst offenders, just some random small guys), but any freedom comes with a small chance of responsibility.