Its The Guardian, they are about as far removed from Trump and his base as its possible to be. Not that i approve of what their doing here, just explaining the motivation.
His guilt over Russia involvement can be inferred by his constant obsession and attempts to discredit typical law enforcement investigation practices. It is a big deal to have a sitting president acting similar to how a guilty defendant would with (1) a video inviting computer hacking, (2) documented lies or rewrites of "official" statements about a Trump tower meeting of senior Trump campaign officials with the representatives of the invitees, (3) an announcement of an upcoming press briefing about contents (emails) of the hacking target made at the time of the meeting, (4) news reports of surveilled increase in hacker activities at the time of the hacking invite.
All of the above are not credit-giving or childish. At the same time, an alternative of explaining government policies and trade numbers would likely not get through the electorate, and in my opinion unlikely to change hardened or media-saturated minds.