It's your duty to gank every lane all the time and win them the game.

It is your responsibility to nip that falsehood in the bud as soon as the picking stage. It helps to make a couple of phrase macros you can paste, e.g.:

Team: understand that I am playing a pusher hero, not a ganker. As such, I will not come to help gank on other lanes, except under circumstances, because three against two is not big enough of an advantage and it can fail. Instead, you two supports come smoke gank mid, three on one has a much higher chance of succeeding and we prevent their mid player from snowballing. I would gank on side lanes if and only if: 1. I can bottle a suitable rune, so put down some rune wards for me and have the courier flying at 3 minutes. 2. You know how to pull creep equilibrium towards our tower so that the enemy is more exposed. If you cannot satisfy that, I will stay mid.

If you die vs the other midder, you will get reported.

Then keep your cool, show your best behaviour and just let them waste their reports. The reporting system is automated and looks at trends and time frames. Reports that are spurious are thrown out, as such you don't have to fear any repercussions from that kind of rage reporting.

If you had a tough time on your lane, no body helps you in catching up (nobody stacks the jungle)

As mid, you can and should stack the adjourning hard camp yourself. If Radiant, you can also stack your Ancient camp. Push your wave into the enemy tower at the appropriate time so that you do not miss any last hits while you walk to and from a camp.

Supports never roam mid, they just stand near their carry and try to harass the enemy.

Encourage them to buy a smoke and gank mid. There are even suitable phrases on the chatwheel for this manoeuvre.