But isnt that what everyone is saying Johnston was supposed to do? Isnt that what "why didnt he fortify Snake creek Gap" is all about - that he didnt make a fortified position to sit behind?
Nope. They are saying that he made no attempt to safeguard it at all, does not seem to have recognized its' importance, and may not have even known that Snake Creek Gap existed. For example, Cantey arrives in Resaca on May 5 and was ordered to move to Dalton on May 7, cancelled at Noon on the 8th. Even then, he is ordered to hold his troops ready to move to Dalton by rail at short notice. Cantey was unfamiliar with the area and no one seems to have told him Snake Creek Gap existed (it is not visible from the town).
He also seems very insensitive to being outflanked through it on the 11th and 12th, when he is getting reports from his observers at Dug Gap of a very large Union wagon train moving down the valley. Hood goes to resaca on the afternoon of the 11th and reports "no enemy within 4 miles", but at the same time Johnston gets a message from Calhoun that there are 30,000 Yankees between the gap and Resaca.
By the end of the 12th, only IV Corps and 2 cavalry divisions are facing Johnston at Dalton. The rest are either in or near Snake Creek Gap. Polk is now in command at Resaca and Johnston tells him to bring the rest of his force up from Rome. Johnston keeps Hood and Hardee up around Dalton through the 12th, then rushed them down to Resaca.
JJ used an active counter-attack strategy. Around Dalton he used Cleburne to respond to Hooker's probe at Dug Gap and then sent Cleburne, Walker and Hindman to try to smash McPherson, but McPherson had withdrawm. At Resaca he absorbed Sherman's attacks and then counter attacked Sherman's left. The failure to keep McPherson from crossing the river lower down that led him to pull back. Over the next few days between the Oostanaula and Etowah rivers he skirmished with Sherman while looking for another opportunity to strike. He attempted to attack a portion of Sherman's force at Cassville but subordinates bungled the move and the opportunity passed. In those first couple weeks he did lose a lot of ground, but he was not just "Sitting in fortified positions and hoping Sherman would smash into them."
I think the key thing to recognize is that Johnston never seems to actually follow through on these things. There are no vigorous attacks. There is a lot of talk about it -- but it never happens. Point out these things and the buck gets passed to subordinates or up the line to Davis. Somehow it is never Johnston's fault that his "plans" (much too grand a word for his practice) never develop into real action.
Cassville, I think, is overdone. The Hood and Johnston accounts contradict each other. While an attack might have dinged Hooker and Schofield up, it does not look like they would be crushed. The rest of Sherman was already arriving to put pressure on Hardee when the attack flopped, and even if accepted at face value the Confederates are saying a delay of minutes made the entire attack plan unworkable. The next day, Johnston publishes a bulletin to the Army, promising a fight -- then retreats that very night. This is not impressive stuff.
Time after time Johnston gives up important ground in rapid succession. Position after position is shown to be ill-thought out and unprepared. And Johnston is the one who wants to have the Yankees attack his fortifications (he blames Sherman for being too cautious to do it).
Over the next month and a half Johnston tenaciously held onto the great defensive space, slowing Sherman considerably. He defeated Sherman's moves at New Hope Church and Pickett's Mill and launching his own counter strike at Dallas. The lines would then move around for weeks. Sherman tried to manoeuver and Johnston attacked him at Kolb's Farm. Sherman than obliged with the "smash into them" at Kennesaw. Other than Kennessaw, JJ did not have a "passive hope-they-attack-and-die plan". But he could not stop the fact that Sherman had such a numeric edge he could keep moving columns around him.
May 6 -- Campaign starts
May 9 -- McPherson comes through Snake Creek Gap and almost breaks the RR
May 13 -- Sherman moves on Resaca
May 15 -- Sweeney's division crosses the Oostanaula again at Lay's Ferry, flanking Resaca. Johnston retreats.
May 16 -- Johnston intends to stand at Calhoun, decides the position is no good, retreats
May 17 -- Johnston intends to stand at Adairsville, decides the position is no good, retreats
May 19 -- Johnston plan to attack at Cassville falls apart. About 10 PM, Johnston orders a retreat.
May 20 -- Johnston is across the Etowah, Sherman closing up on the north side.
May 21 -- Sherman pauses his advance to bring his supplies and LOC forward, rest his troops.
May 24 -- Sherman has crossed the Etowah
So in about 18 days, Sherman has advanced his position about 60-65 miles. Looked at another way, Johnston has retreated 60 miles in 12 days (May 12 when he retreats from Dalton).
Kennesaw is the only place where ***Sherman*** decided to attack directly into Johnston's fortifications. There were a lot of times where Johnston sat behind fortifications waiting and hoping for Sherman to attack him. Sherman just kept on outflanking him and Johnston just kept on retreating.