Lux is a passable support, so if a player really wanted to support, he or she could go Lux.
However, I think the reason they made the new champion pool solo laners is because laning is the easiest thing to do. You don't need to buy a special item, you're allowed to kill minions, you do lots of damage, and the burden isn't on you as much to ward. I tried out Lissandra mid in my first game, and with my experience in Warcraft III AoS maps, I did all right.
However, when I didn't get mid, my friend recommended support to me. I listed out all the free champions, and he said that I could go Lux. My first experience as support was extremely confusing.
"Okay, so you buy the Spellthief's Edge and use the rest of your gold on Health Potions."
"Okay," I replied.
However, in the back of my mind I was thinking, "Wow, I would have never known to buy that if it weren't for him. Support sounds complicated already." I didn't even know that there were other support items; later, during my first game as support Galio (yep, I thought his kit sounded like a support kit), I bought a Spellthief's Edge instead of a Relic Shield because I thought that the Spellthief's Edge was the support item.
"Okay, now come bot. You're going to help me leash for the jungler."
Leash???
"Yeah, you just auto attack the Gromp until it's low, then you leave with me."
I was completely lost. Why couldn't we all share the EXP?
"The jungler needs level two, we don't. We can take minions in lane."
I took his word for that.
Then I asked him, "So Nathan, what do I do now?"
"Just... uh, auto attack them and harass them with your E. That gives you gold."
"Oh, I got Q."
"Stop attacking the minions! Supports don't take minions, Jeff. They get all the gold from their item."
Jeez this role is complicated, I remember thinking. How would I have known to do any of this stuff without my friend?
"Not even one?"
"No, the ADC needs all the gold."
"Can I attack the minions so that they're lower health for you? Also, what's ADC?"
"No, that messes up my timing, and attack damage carry."
"What if I do it by accident?"
"It's okay, but try not to."
"Okay, so you know how I told you to auto attack the enemy? Don't go so far out to do that."
"But then I have no other job. You told me not to kill minions, so I'm just sitting around doing nothing. I've got to attack them."
"That's how you got yourself killed. You need to be safer. Remember, they have two people, and if you harass them when I'm getting cs, then I can't help you and they can kill you. You're also super squishy."
I was even more confused. All I did was deal damage to the enemy, but I wasn't supposed to be dealing damage to the enemy all the time?
"You know, actually, when the minions come under tower, auto attack the ranged minions once if the tower is targeting them. I can't get the cs if you don't."
...what the heck was he talking about?
"Actually don't worry about that, you'll learn in time."
"Okay, so how much gold do you have."
"1350"
"Get a Sightstone and upgrade your gold item."
I look at the Sightstone's description and choose not to buy it. "It looks pretty crappy," I think.
Later, my friend tells me that the laning phase is over and we can roam.
"So now what do I do?"
"You just walk around with me and ward bushes. If you see an enemy, hit them with your spells."
"Can I kill minions now?"
"Only if there aren't any people nearby. They need the gold more than you."
I can't imagine learning support without the help of someone experienced. That game was so confusing, mostly because support is a bunch of concepts that I had never learned before. Not attacking or killing minions was weird, getting gold by attacking enemies was weird, warding was weird, and leashing was weird. Later, when I tried out Alistar, I learned I had to buy a Relic Shield, which was also really weird since I was so used to auto attacking enemies for gold.
I think it's all right to encourage players to play laners in the early levels. Support is complicated, and players can learn it after they've gotten their bearings with the easiest role.