I think stadium concerts are full of people who don't go to many gigs and so don't have the better experience of the smaller venues.
Any gig where a guy standing at the back couldn't hit the lead singer by throwing a bottle has too many people at it.
I get your poiint, and Kinboshi's about stadium/outdoor gigs.
I've been to a few of them & I tend to feel they need to be either a) a great show, or b) a great crowd.
I've seen Springsteen, U2, Simple Minds & Runrig as headliners at Stadium/outdoor gigs. Loved each one for different reasons.
Springsteen - fantastic concerts lasting about 4 hours, sound quality excellent (as you'd expect from a stadium veteran). No special effects/support acts - just the Boss, the E-Street Band & the music. Although Edwin Starr blew him off the stage singing WAR at Bramhall Lane.
U2 - Spectacular show, sound quality poor (Murrayfield has great accoustics for a crowd - too much echo for a gig) - was near the speakers though so didn't suffer the echo effects too much. U2 are great showmen. Support couldn't hadle the venue though.
Simple Minds - at Ibrox - huge 'homecoming gig' - crowd were mental, then the band started with Waterfront & the night went ballistic. I thought the sound was good, and people who listened to it from outside said it was as well, but the atmosphere made it for me.
Runrig - live at Loch Lomond. Another gig where the sound seemed OK, but as the whole crowd were singing along & having fun I don't think it mattered.
I've been to small venues, I love getting up close to the bands for the concerts, but sometimes the sheer spectacular effect of the outdoors gig has a quality all of its own.