There is no lack of tanks or healers , but there is serious lack of people wanting to fill that role.
So far ive tanked WC while two warriors were DPS.
Ive also healed in WC with a level 18 priest as DPS. (This with a leader that was hunter and was spamming the chat for dps & healer but wouldnt let me join as dps because i was gonna roll on same stuff as him. But gave up when they couldn´t find a healer)
Tanked BFD with 2 warriors in group.
Also numerious of times ive got messaged by either priests to heal in instances or by warriors to tank.
ive got no issues to heal or tank as druid even though im feral spec. But its annoying that people get mad when i roll on agility gear as a feral tank or int+sprit gear , even though i fill both roles and gimp my self by having to have 1 extra set of gear in my bags.
Why would they get mad at a feral tank rolling on agility gear? Agility is one of your main stats, with def/stam/hp. Or do you mean they get angry at you rolling on int/spir when you’re tanking?
If you want to roll on your other spec, you should probably say before you start.
Honestly, tanking and healing in WoW Classic is something any class with some threat-generating abilities and healing abilities can do, regardless of spec or gear (at least while leveling).
I’ve met warriors who came from Retail and think they can’t tank because they don’t have the gear or the talents for it. I told them to just equip a shield, pull the mobs, generate some threat and rely on my heals to stay alive. Usually that works out just fine.
Same with priests who came from Retail and think they can’t heal because they are specced into Shadow. Just get your Lesser Heal and Heal from your class trainer and start healing, it doesn’t matter if you have little or no talents in Holy, just bloody do it.
I think, if more people figured this out, we’d all have an easier time together in Classic.
Yeah, it’s like having Spirit Tap and Wand Specialization (which is what all priests have at 20lvl) suddenly makes them better at DPSing and/or worse at healing…
Meanwhile, my gf who levels a priest together with me just DoTs the skull and wands it while healing me, also sniping the mob with Mind Blast when it gets low, making just as much use of those talents as a “DPS priest”.
If my girl, who’s been playing this game for 2-3 months, can do this, then you, retail “DPS priests”, can also do it. It’s not like you will use Mind Blast (due to threat) or Mind Flay (due to wands) anyway…
By the time they notice, you are already progressing inside the dungeon. Nobody in their right mind would stop at that point, kick you, replace you and continue. Once you are in, you are, man.
You and me know that
But i just wanted to show that there are such people out there…and those guys are the ones who complain that there are neither tanks nor healers
Well I can understand everyone who does not want to tank for a PUG. If it’s only about the loot, I guess most groups are ready to discuss the terms (roll on dps gear etc) for getting a tank. I myself only tank for my guild because PUGs can suck so much its unbearable.
But we also have a DPS Shaman in our guild who refuses to heal. And that also sucks, because several times we have been waiting for Healers because of him. He’s in the early 40s ffs, should be able to heal everything with ease. But he’s one of those guys who refuses even to emergency heals because he needs his mana to do damage. Yes, I’m a bit salty about this.
Ive had a hunter whining i rolled on agility leather gear because strenght & stamina is my main stat when tanking.
Then again might be true for bear form but all ferals pretty much stay 90% i catform while questing. Ive also been denied joined groups by rogue/hunter leaders coz we contest the same gear.
Not a bid deal though. Just from my experience people were not like this in vanilla though. I really mostly do dungeons for quests. Dont understand why people are so tryharding on level 30 gear that will get replaced 5 levels later by something better anyways.
. They are afraid of the outside world 
. So that’s where they all are.