Because people want to feel plugged in, and be getting value for their money TR. I know this may sound completely oblique to you, but some fans want different things than you do, out of their hobby.
Back when there was no Internet, the club itself was much more approachable, the players were approachable, and it was a predominantly a demographically based game (i.e. players came from the area & things). It was about passion and pride in the jersey and the area. Believe it or not, players actually had to work outside of playing the game !!
Things have changed. It's strictly a business now. And as businesses go, goodwill is extremely important. If there is no goodwill, you can't complain about low memberships, poor attendances & unhappy customers. That then leads to lack of funds, rellocation & all that other ugly stuff - and guess what - it's happening.
I've never seen the club have so many fans leaving the game. End of the day, Manly's media management is deplorable. Their social media is sub par. If & when a team is winning, that's not so crucial. When a team is lacking in performance (both on and off the park), there is allegations of match fixing surrounding the club, there is talk of disharmony in the playing group (Stewart / DCE), there are unknown quantities in Matai / Stewart & others, club legends have or are retiring, staff are getting sacked, social media is paramount to drive enthusiasm and positivity.
I'm actually quite surprised you don't get that, BUT, I can't be a hypocrite & tell you everyone wants different things out of their hobbies, then criticise you for your opinion on it, so I'll finish by saying each to their own, but I feel the opinions of the majority here has a whole lot of merit.
And guess what - I bet they STILL love to see the team winning, sitting on the hill & enjoying a cold pie and warm beer. The fact that they can clearly see our club lingering behind all the others on Social Media doesn't change that.