There's a pattern I'm beginning to notice throughout this conversation. Folks who prefer to allow players to initiate their own rolls tend to frame the DM who hands out auto successes and failures as doing so based on the quality of the player's description. "I'm not very charismatic, so rolling in social interactions gives me a better chance to succeed." "I don't want to unfairly punish players for not being good at descriptions." "DMs shouldn't give bonuses for good flavor text or penalties for bad flavor text" etc. are all sentiments I've seen from the pro player-initiated rolls side.
However, folks on the anti player-initiated rolls side don't frame it this way. For me, auto-successes and failures are not passed out based on "good roleplay" (*hurk*). I base them entirely on how likely the announced approaches are to achieve their stated goals. So, let's take a simple example: there is a McGuffin the players are searching for. It is hidden under a cardboard box in the middle of an empty room. If the players describe looking under the box, there is no chance they will not find the McGuffin. If they do not look under the box, there is no chance they will find the McGuffin. If a player describes in exquisite detail the plethora of methods they employ to search the room, they will not succeed if those methods don't include looking under or moving the box. On the other hand, a player who says simply, "I look for the McGuffin under the box" will succeed. No roll will be required in either case. The determining factor is not "good roleplaying" (*hurk*), it's their methods and those methods' likelihood of accomplishing their goals.
This goes as much for complex social interactions as it does for searches for poorly-hidden McGuffins. The player of the dashing male rogue can compose and perform a shakespearean-quality sonnet to try to seduce the princess, it's still not going to work if the princess is gay, because the approach (reciting a romantic sonnet) doesn't have a reasonable chance of succeeding at its goal (seduce the princess). On the other hand, if the player of the butch female half-orc awkwardly stammers "I umm... Flex my muscles, and... Wink at her?" will at least get a chance to roll because her approach (play on the princess's preference for buff women) does have a reasonable chance of success and a reasonable chance of failure. Maybe the princess has a secret fetish that the players could have discovered by digging up rumors within the city, and if the half-orc player's approach involves taking advantage of that fetish, it might auto-succeed, even if the action has no actual description. "I try to seduce the princess by subtly hinting that I'm into bondage too" is a perfectly valid action, with a goal and an approach. And if that approach has no reasonable chance of failing to achieve that goal (hey, she's really into bondage), it won't require a roll, regardless of the "quality" of the description.