Yeah it is. My monk with 80AC seems to get hit 95% of the time in epic desert. And if you lower to-hits then extreme AC builds with 100AC become near invincible.
It would be a mistake to expect every group to have a divine caster with recitation or a bard with AC song, kept up on each player. You can't balance around such a restriction unless you want to reduce gameplay options.
You're looking at a character decked to the hilt with end-game gear and tomes. How are new players supposed to compete with that, if they're complaining about being declined for not having something as simple as a single heavy fort item? Also, the AC that a pure cleric, fvs, THF bard/pal/fighter (non defender), barbarian, sorc, wizard can reach is generally much lower than my 20 ranger, especially if WF.