Home and private poker vs online poker and casino poker?

Every medium sized city includes hundreds of weekly poker games going on inside it. Tuesday, Wednesday and Thursday nights countless husbands make poker widows of their wives and gather somewhere to play for several hours. There’s no background noise of slot machines, no rake, no self-proclamations about anyone being a poker professional, and no fanfare.

But there is frequently plenty of money on the table. And every player can see the same cards the same shuffle the faces and the hand and eye movements of all the other players.

The question nagging me is why the people who play online and see themselves as poker experts and profess their professionalism as gamblers here are doing it online, where it’s about memorizing or owning statistical software instead of out there where the rubber meets the road?

What brings a person to put money on an imaginary table online and trust an environment he/she would repudiate and laugh off at the hint or suggestion if the same environment was offered at a brick and mortar casino?
Maquis: Thanks for the insightful answer involving your own circumstances and why. My question was actually intended for a slightly different type of answerer: The cadre of shout-it-from-the-rooftops ‘professionals’ here.

And the intended emphasis was home-private games versus casino and online games. I probably was to vague in my wording.

Gracias,