Masha-Allah.
True the Virtues (Amaal) are very important but Prayers (Ibaadaat), are also just as important.
Sincerety of intentions, Ikhlaas-e-niyaat, is what separates the ibaadaat done to show to the world your piety or show only to Allah, God Almighty, your sincerety.
This show of unity, as we see in these prayer gatherings, is also very important specially in today's hectic times, we need all the unity we can gather. This is why a Prayer in Jamaat (in Masajid), is many times more rewarded than prayer done in solitude at home.
Its Blessing are enormous, not just what we don't see, but in practical sense, when we go thru physically to a central gathering place for a prayer, we make more effort, and our HEARTS become more united toward each other, naturally.
This is what we need to focus even more, the sense of UNITY, caring for our brothers, being humble and meeting our neighbors, friends, feeling as ONE community, and prayer in a large gathering does that. You meet your neighbors, say Salaam to them.
I've noticed lately, while going on Vacations in Pakistan, that the community in Pakistan (Islamabad in particular), is much the same as in USA or Europe. No one talks to one another, just rush to jobs and homes. Going to Masajid, regularly, everyday, for atleast one prayer in Jamaat, brings people closer. Care for one another, that is the main purpose, as well as collectively bowing before Allah Almighty to admit our weaknesses.
May Allah have mercy upon us all.
And yes, the Imam-e-Kaba might be just a man, and people are not PRAISING him, by going there.
This is the specially KARAMAAT, Allah Almighty has bestowed on the the Imaam of Kabah, for being 1 in 1.5 Billion Muslims to have the honor of leading the prayer at the Holiest of all the holy places in this world.
Again, SINCERETY OF INTENTIONS is what Allah sees. Where and behind whom you offer prayer may have some benefit, but not As big as WHERE YOUR SINCRETY and ATTENTION lies. If your heart is wandering in the WORLD, when you are Making Salaat in Kabah Shareef, what do you think are the chances of acceptance. But due to HOLINESS of Kabah, the chances of your acceptance would be ENORMOUSLY higher than if you were praying alone at HOME.
Every person who has a chance to Make HAJJ pilgrimage is a "CHOSEN ONE", otherwise, all 1.5 billion of us would have had the chance. But not all of will get that chance, only those whom Allah will choose. Same is the case, with only those who were LUCKY ENOUGH, had the chance to make the prayer with Imaam-e-Kabah,
Yes the sincerety is important, we should not defray from that, but, there are some "chosen people" like Holy Prophets of Allah Almight, the Ashaab-e-Karam, and in our society, their are still some Wali-Allah, and certainly the Imaam-e-Kabah.
We Muslims LACK a CENTRAL Leader of Muslim Ummah, and the ONLY place where we see any UNITY is at Bait-Ullah Shareef, under the leadership of ONE leader, the IMAAM of Kabah. May Allah have mercy on him, and on All of us.
Ameen.